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Re: Differences L.A. and Magnum? And which is better?
[Re: 68Bullit]
#1009834
06/09/11 10:33 AM
06/09/11 10:33 AM
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Joined: May 2003
Posts: 15,487
Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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magnums started in 92-93 they are a roller cam block,they have the closed chambed heads that have pedistal rockers and oil up thru the lifters and push rods. there is a slight differance in the balance of the crank/rods/pistons it has higher comp ratio than any of the older LA engines. the heads are about the best flowing heads for a SB now days and are swaped on to some older LA block with some mods to make a pre-mag hybred engine. 85 started the LA engine with a roller cam and non oil thru lifters and shaft mounted rockers 89 for the roller block pre-mag 360 engines they went to oil thru roller lifters and hollow push rods oiling the shaft mount rockers along with it oiling the old LA style thru the block/heads...oils both ways in 1990 or so. more gain with the mag blocks as it is already for roller cam upgades with out machine work the mag heads dont take much lift but can be worked for anything in the retro roller cam line up. my LA 88-4-v 318 has 360 heads but as all 4-v engines had a flat tappet cam,I used all 1990 oil thru roller gear and hardware to swap in a lunati voodoo roller cam with some comp 901-16 springs next up grade will be a set of mag heads for the LA/magnum hybred combo,it is ready to oil thru the lifters and PR for the mag head swap the magnums have a short nose cam and no mech fuel pump,but you can get an extintion to run one with an LA t-cover. the old LA t-cover will swap to the mag engine,heads may not have correct bolt holes for alt brackets IIRC intake bolt angle is differant and can be redrill to LA bolt pattern to up the intake choise. just a few things I remeber right off hand  hope that helps some 
Last edited by scratchnfotraction; 06/09/11 10:37 AM.
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Re: Differences L.A. and Magnum? And which is better?
[Re: scratchnfotraction]
#1009836
06/09/11 11:35 AM
06/09/11 11:35 AM
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
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Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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Some food for thought, the crate 300 hp 360 is a stock 360 magnum with a carb intake and headers. The 385 hp version has flat top pistons for more compression, and a different cam. Hughes has kits to put a high lift, longer duration cam into an otherwise stock magnum motor, and if you shave the heads, you can duplicate the 385hp build for the cost of a junkyard 360, their cam/springs/retainers, and machine costs to shave the heads... Or $1000-1200
And magnum blocks have the ears to accept LA mounts for a bolt in deal
**Photobucket sucks**
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Re: Differences L.A. and Magnum? And which is better?
[Re: 70Cuda383]
#1009837
06/09/11 12:20 PM
06/09/11 12:20 PM
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Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
HotRodDave
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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Actually the 300 hp crate motor has a smaller cam than the stock magnum motors. The 5.2 magnum cam is slightly better than the 5.9 cam, not enough differance to go out and buy one but if you are like me and have a bunch of both sitting around it is always nice to be able to throw in a 5.2 cam in a 5.9. Also the 300 hp crate engine used a crappy M1 dual plane intake, if you build your own then the eddy air-gap is a lot better intake, combine it with some decent headers and you will be over 300 hp for sure. I have always wanted to see a dyno (or drag strip)shoot out between a 1968 340 4spd motor and a 2001 magnum 360, both could be outfited with the same intake (air-gap)and headers (TTI) to even things up and I would put some money on the 5.9 if both were truly bone stock internals. A few other things about those magnum motors is the heads flow about the same, mabey a hair better than an X head but the combustion chambers and port shapes are waaaaaaayy better at mixing fuel and air. Also a magnum has lighter valves. Also just to clarify ALL 318s magnum, poly and LA are internally balanced while the 360 magnum and LA are both externally balanced but slightly different from each other because the piston and rod are lighter in the magnum. All magnums use the same oil pan where the LAs had a different one for the 273 318 340 and the 360 had its own. The intake bolt pattern is totally different for LA and magnum, magnum heads can be re-drilled to use the LA intakes that are more readily available used. Magnum rods can be used in an LA but not vice versa with out a piston swap, the top of the magnum rod is slightly narrower. Cranks are the same.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Differences L.A. and Magnum? And which is better?
[Re: 70Cuda383]
#1009839
06/09/11 01:26 PM
06/09/11 01:26 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
Some food for thought, the crate 300 hp 360 is a stock 360 magnum with a carb intake and headers. The 385 hp version has flat top pistons for more compression, and a different cam. Hughes has kits to put a high lift, longer duration cam into an otherwise stock magnum motor, and if you shave the heads, you can duplicate the 385hp build for the cost of a junkyard 360, their cam/springs/retainers, and machine costs to shave the heads... Or $1000-1200
And magnum blocks have the ears to accept LA mounts for a bolt in deal
actually early 380hp crate motors were stock truck long blocks like the 300 hp motor, but with different valve springs, cam, and a single plane intake.
also, the location of the bolt holes for the intake are the same between LA and magnum, it's the angle that's different. LA's are ~7-8 degrees from perpendicular to the head face, while the magnums are ~45 degrees from the head face (perpendicular to the ground)
and all magnums use a 360 style pan.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Differences L.A. and Magnum? And which is better?
[Re: patrick]
#1009840
06/09/11 01:44 PM
06/09/11 01:44 PM
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Joined: Jan 2011
Posts: 15,879
Central Florida
larrymopar360
Stud Muffin
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Stud Muffin
Joined: Jan 2011
Posts: 15,879
Central Florida
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True. The Magnum crates did use a production truck block. I have owned two of the 360 crate motors.
Facts are stubborn things.
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Re: Differences L.A. and Magnum? And which is better?
[Re: patrick]
#1009842
06/09/11 02:04 PM
06/09/11 02:04 PM
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
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Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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Quote:
Quote:
Some food for thought, the crate 300 hp 360 is a stock 360 magnum with a carb intake and headers. The 385 hp version has flat top pistons for more compression, and a different cam. Hughes has kits to put a high lift, longer duration cam into an otherwise stock magnum motor, and if you shave the heads, you can duplicate the 385hp build for the cost of a junkyard 360, their cam/springs/retainers, and machine costs to shave the heads... Or $1000-1200
And magnum blocks have the ears to accept LA mounts for a bolt in deal
actually early 380hp crate motors were stock truck long blocks like the 300 hp motor, but with different valve springs, cam, and a single plane intake.
also, the location of the bolt holes for the intake are the same between LA and magnum, it's the angle that's different. LA's are ~7-8 degrees from perpendicular to the head face, while the magnums are ~45 degrees from the head face (perpendicular to the ground)
and all magnums use a 360 style pan.
I made a post a few weeks ago asking about the cam in the 385 hp version of the magnum crate motor, and it as said that they are using the aftermarket "R/T +10" cam that's in the 230 degree duration area...not the stock 360 truck cam.
the truck cam is all done by 4800 rpm, as it's geared for low end torque, and matched with the beerkeg intake, which runs out of flow at around 4800. why would they use such a low rpm cam in a 385hp crate motor that'll spin to at least 6,000 rpm in a carb application?
**Photobucket sucks**
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Re: Differences L.A. and Magnum? And which is better?
[Re: 70Cuda383]
#1009843
06/09/11 03:33 PM
06/09/11 03:33 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,376
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To the O.P.
Wow, your question got me a long way off track. Also almost everyone else. Wish you had said what you had first, would have saved a lot of extra typing.
Your question is basically, "Should I switch blocks to be able to use a hydraulic roller retrofit cam? I am running a 360 with XE268 and Edelbrock heads right now and want more cam. Putting a hydraulic roller in my existing block is going to cost $1000."
My answer to THAT question is, Yes, if you have a good machine shop that can bore another block to fit your pistons for a reasonable price and also if you can find a roller block for a good price.
BUT, you don't have to go to a Mag block at all. You can use an 89-93 360 roller block or the 5.9 Mag block, either one should allow you to use all of your old parts except for the new cam, lifters and pushrods. Of course you need to get the roller lifters and lifter retainers but they are available used for little money. Pushrods I am fuzzy on, the stock roller lifter pushrods might even work.
R.
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Re: Differences L.A. and Magnum? And which is better?
[Re: 70Cuda383]
#1009844
06/09/11 04:26 PM
06/09/11 04:26 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
Quote:
Quote:
Some food for thought, the crate 300 hp 360 is a stock 360 magnum with a carb intake and headers. The 385 hp version has flat top pistons for more compression, and a different cam. Hughes has kits to put a high lift, longer duration cam into an otherwise stock magnum motor, and if you shave the heads, you can duplicate the 385hp build for the cost of a junkyard 360, their cam/springs/retainers, and machine costs to shave the heads... Or $1000-1200
And magnum blocks have the ears to accept LA mounts for a bolt in deal
actually early 380hp crate motors were stock truck long blocks like the 300 hp motor, but with different valve springs, cam, and a single plane intake.
also, the location of the bolt holes for the intake are the same between LA and magnum, it's the angle that's different. LA's are ~7-8 degrees from perpendicular to the head face, while the magnums are ~45 degrees from the head face (perpendicular to the ground)
and all magnums use a 360 style pan.
I made a post a few weeks ago asking about the cam in the 385 hp version of the magnum crate motor, and it as said that they are using the aftermarket "R/T +10" cam that's in the 230 degree duration area...not the stock 360 truck cam.
the truck cam is all done by 4800 rpm, as it's geared for low end torque, and matched with the beerkeg intake, which runs out of flow at around 4800. why would they use such a low rpm cam in a 385hp crate motor that'll spin to at least 6,000 rpm in a carb application?
stock long block EXCEPT The cam...early 380hp crate motors used stock pistons, not flat tops. later ones used flat tops. IIRC board member Zippy has a pretty good understanding on the history of the magnum crate motors...
cam in all the hotter magnum crate motors was IIRC 288/292 adv ~230@.050 on the intake, and .512" lift for both lobes on a 108CL
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Differences L.A. and Magnum? And which is better?
[Re: dogdays]
#1009845
06/09/11 04:29 PM
06/09/11 04:29 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
To the O.P.
Wow, your question got me a long way off track. Also almost everyone else. Wish you had said what you had first, would have saved a lot of extra typing.
Your question is basically, "Should I switch blocks to be able to use a hydraulic roller retrofit cam? I am running a 360 with XE268 and Edelbrock heads right now and want more cam. Putting a hydraulic roller in my existing block is going to cost $1000."
My answer to THAT question is, Yes, if you have a good machine shop that can bore another block to fit your pistons for a reasonable price and also if you can find a roller block for a good price.
BUT, you don't have to go to a Mag block at all. You can use an 89-93 360 roller block or the 5.9 Mag block, either one should allow you to use all of your old parts except for the new cam, lifters and pushrods. Of course you need to get the roller lifters and lifter retainers but they are available used for little money. Pushrods I am fuzzy on, the stock roller lifter pushrods might even work.
R.
mag block (except for EARLY production ones) will need the #2 and #4 cam journals drilled for head oiling, or you'll have to plumb the heads externally like a big block indy head, or you'll get no oil to the rocker fulcrum with LA heads.
what do you have for pistons currently? does your existing rotating assy need to be refreshed?
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Differences L.A. and Magnum? And which is better?
[Re: patrick]
#1009846
06/09/11 06:30 PM
06/09/11 06:30 PM
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Joined: Mar 2008
Posts: 571
Western NC
68Bullit
OP
mopar
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OP
mopar
Joined: Mar 2008
Posts: 571
Western NC
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Dogdays, this is all info that I needed anyway, so nobody got way off track, nor can there be too much typing on Moparts.... right???  I'm really glad to have this thread now with all this good info, so Thanks for your time, and Thanks to everyone else. Patrick, my current rotating assembly is good. Had it about 3 years now with ocassional driving and one time down the strip. Probably have like 2000 miles on it, tops. Nothing wrong with it beyond normal engine wear. Sounds like maybe I'm ok to keep this block, and maybe better off money wise to just continue on with what I have?
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Re: Differences L.A. and Magnum? And which is better?
[Re: dartgame]
#1009848
06/09/11 06:47 PM
06/09/11 06:47 PM
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Joined: Mar 2008
Posts: 571
Western NC
68Bullit
OP
mopar
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OP
mopar
Joined: Mar 2008
Posts: 571
Western NC
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Quote:
Why bother switching blocks at all. There are hyd. roller lifters that can fit into the old blocks. Check mancini racing. Or cheaper yet, stuff a hotter flat tappet into your engine.......
No doubt, but I don't really see a grind that I like above the XE 268 in the CompCams flat tappet line. The 274 might still be available and if so, why change it then (to just a 274, for no more gain than a 274 will give me over the 268), then there's the 284 that will take away my good idle and maybe even a portion of my power brakes. So, this is why I'm thinking of going roller with the CompCams because I DO like the grind of the XR-280HR-10, and how this particular cam will keep me streetable, etc.
Of course, as far as flat tappets, I could venture into another brand besides CompCams to see if there is something I like but I also think if I'm gonna change it, to just change it to a roller and quit worrying about special oils, and the general worries of flat tappets, etc.
Regarding the heads on the Magnum engines..... Are they as good as stock Edelbrock heads that I have on my L.A. application????
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Re: Differences L.A. and Magnum? And which is better?
[Re: 68Bullit]
#1009849
06/09/11 07:28 PM
06/09/11 07:28 PM
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Joined: May 2003
Posts: 15,487
Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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upgrade to a pre-mag roller block or retro fit you block for roller lifters which are more $ than stock roller lifters. ues the edelbrock heads on the pre-mag roller block to retain the LA style oiling to the shaft mount rockers. edelbrocks are better than mag heads in more than one way,lighter,can run higher comp ratio,flow better,look better you can use all the stock roller lifters and hardware in a pre-mag block with any of the retro roller cams. my high mileage 88 pre-mag 318 with LA 360 heads got some high milage 1990 roller lifters and hardware back in 07' with the lunati roller cam and comp 901-16 springs stock retainers/locks/seals pushing almost a full 300,000 miles(heads never off) and drive it hard everyday and not a single problem with it yet...worn rings is another story though  cheaper to run stock roller lifter in a stock roller block,you can get new replacements for around 100$ at the mopar dealer. retro fit may need some block clearance/grinding to fit the link bars in. you can check with member OU812/IMM-brian he has some nice drop in rollers that have had some mods done to correct some short falls of the roller lifters like longer skirts,bearing oiling,oil groove in lifter,link to intake side not the block side ect.. need to do all the home work to save some cheez then decide on whats whats pick up a god used pre-mag engine and build it then swap and have a good spare engine 
Last edited by scratchnfotraction; 06/09/11 07:34 PM.
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Re: Differences L.A. and Magnum? And which is better?
[Re: 68Bullit]
#1009852
06/10/11 11:03 AM
06/10/11 11:03 AM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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what's the rest of the combo (gearing, converter stall, tranny, compression, intake, carb, etc?)
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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