Moparts
New build: LA or Magnum??
Posted By: ewolfe
New build: LA or Magnum?? - 11/01/09 04:58 PM
I'm helping a buddy start a 69 Dart build and he has a 340 short block that needs rebuilding. I was wondering since he still has no heads, should he sell the 340 and get into a 5.9 magnum for the heads and roller block? The Dart is run-of-the-mill, so originality is not his concern. His concern is good power, drivability and longevity. If a magnum is the way to go, which years should we look for?
Thank a ton for all your input as I have no experience with magnum engines other than the 5.2 in my 99 Durango.
Posted By: RUNCHARGER
Re: New build: LA or Magnum?? - 11/01/09 05:13 PM
I really like the Magnum heads. If it isn't a 340 car I would sell the 340 and start with a 360 Magnum with a stroker crank. If it is a 340 car I would be tempted to put Magnum heads on the 340 block. I think Hughes or someone like that sells new Magnum heads (the original heads are crack prone).
Sheldon
Posted By: ewolfe
Re: New build: LA or Magnum?? - 11/01/09 05:28 PM
This wont be a high dollar build, more like a smaller budget build. There won't be any money for a stroker kit or new heads. We'll have to depend on boneyard heads and stock crank. This is a standard GT dart with 318, nothing special. We would like to go with a roller and magnum heads, but we don't know which year of magnum to look for...which heads would flow best and the like.
Thanks
Posted By: HotRodDave
Re: New build: LA or Magnum?? - 11/01/09 08:39 PM
I would get a 2000-02 magnum if I had the choice but they are all very close. The heads I have recently found out have slightly bigger ports not much but a hair, 5cc on the two sets of later heads I have here. Also they had a slightly better cam, the same cam as the R/Ts originally had, the last couple years they all got that slightly revised cam. You should be able to get a good low miles one for $500-700 and bolt on headers and an RPM air-gap intake and make close to 350 HP. The 300 hp crate motor has made 320-325 on several different dynos when it has good headers, and it had a smaller crappy cam and crappy M1 intake. With a re-ground cam and better springs you could get close to 400hp.
Posted By: dodgeboy11
Re: New build: LA or Magnum?? - 11/02/09 02:22 AM
I would get a magnum short block. Look for 93 and later 360. Reason I'd go short block is the factory heads crack. I think I've seen one set off a take-off engine that weren't cracked. Anyway, get the short block and go either Edelbrock magnums or those new indy cast iron magnum heads. I think there's one other brand out there that's decent. RHS but I don't know where to find their stuff. I really like the eddies though because they have 7/16 studs and you use small chevy rockers. Lots of those around and very reasonably priced.
Magnum R/T heads are another good head but they need work to flow any better than a factory magnum head. At least mine needed work...
Flowed a whopping 210 cfm.
Posted By: can.al
Re: New build: LA or Magnum?? - 11/02/09 02:35 AM
...'69 Dart,good power/driveability;
this is a very easy question to answer.
Does he want a '69 340 Dart or a '69 360 magnum Dart?
.....al
Posted By: patrick
Re: New build: LA or Magnum?? - 11/02/09 12:46 PM
Quote:
I would get a magnum short block. Look for 93 and later 360. Reason I'd go short block is the factory heads crack. I think I've seen one set off a take-off engine that weren't cracked. Anyway, get the short block and go either Edelbrock magnums or those new indy cast iron magnum heads. I think there's one other brand out there that's decent. RHS but I don't know where to find their stuff. I really like the eddies though because they have 7/16 studs and you use small chevy rockers. Lots of those around and very reasonably priced.
Magnum R/T heads are another good head but they need work to flow any better than a factory magnum head. At least mine needed work...
Flowed a whopping 210 cfm.
the Indy ones are RHS's hughes sells them starting at $879/pr assembled. the other brand is also austrailian made, Enginequest. Hughes sells theirs as the "Iron Ram" starting at $699/pr assembled.
I have essentially a slightly hopped up 318 magnum ('86 roller cam shortblock, magnum heads) and I'd never go back to LA for a bucks down build. I had my roller cam reground by bullet cams with their HR259/316 lobe, hughes 1110 springs, 2.2L mopar retainers, headers and an RPM air gap (I redrilled the heads to LA intake pattern), and it makes great power everywhere.
Posted By: Mr.Yuck
Re: New build: LA or Magnum?? - 11/02/09 02:13 PM
A 5.2 magnum is even better than a 340 I'd do the 5.9. By upping the cam a little and using an M1 intake, headers...should be a nice strong ride.
Posted By: OrangeProwler
Re: New build: LA or Magnum?? - 07/07/10 12:14 PM
Quote:
I would get a 2000-02 magnum if I had the choice but they are all very close. The heads I have recently found out have slightly bigger ports not much but a hair, 5cc on the two sets of later heads I have here. Also they had a slightly better cam, the same cam as the R/Ts originally had, the last couple years they all got that slightly revised cam. You should be able to get a good low miles one for $500-700 and bolt on headers and an RPM air-gap intake and make close to 350 HP. The 300 hp crate motor has made 320-325 on several different dynos when it has good headers, and it had a smaller crappy cam and crappy M1 intake. With a re-ground cam and better springs you could get close to 400hp.
I located a 2002 engine with 51k miles for $1,100 complete and I think it's expensive. Anyways, with that being said here is a couple questions I have.
Should I worry about cracked heads?
When you say R/T Cam what do you exactly mean? I was under the impression that all 360 Magnums after 95 had only .410 valve lift camshafts? Should I just throw on an intake, carb, distributor on a Magnum engine and run with it?
Posted By: patrick
Re: New build: LA or Magnum?? - 07/07/10 01:19 PM
Quote:
This wont be a high dollar build, more like a smaller budget build. There won't be any money for a stroker kit or new heads. We'll have to depend on boneyard heads and stock crank. This is a standard GT dart with 318, nothing special. We would like to go with a roller and magnum heads, but we don't know which year of magnum to look for...which heads would flow best and the like.
Thanks
honestly, don't overlook the 318 magnums, they perform very well, too....a cam and headers will usually get a 3500+ lb dakota into the 13's if they can hook.
heads, flow wise they're all the same...one of the castings is slightly larger, port volume wise (~10cc)...anecdotally, 5.2's seem to be less crack prone than 360's as far as heads go...not sure if it has to do with the tuning of the engines. '96-up don't have EGR, don't know if that comes into play as far as head cracks, either.
as far as the heads, get some 2.2L retainers, use the stock magnum locks, and use hughes #1110 springs. if you plan on getting them redone, get the valve job opened up to 1.9"/1.605", and have a 75 degree throat cut done to open up the bowls. the OEM valve job is very undersized for the valves (others have found that the stock valve job works with LA sized 1.88/1.6 valves). also, open up the pushrod pinch as much as you're comfortable with, and do a little bowl blending.
if you're planning on tearing it down, I would measure how much in the hole the pistons are, and potentially deck the block. if you can find the thin (.028") Mr. Gasket/MP head gaskets, deck the block to .015" in the hole, that'll yield a tight quench. this may limit cam choices as far as lift and/or duration, but if you stay under ~.520" lift at the valve and ~224@.050 duration, I wouldn't expect a problem.
cam, I'd get it reground by bulletcams because I'm cheap. conversely, hughes sells reground cams for $200+refundable core charge. I'd probably get their HER1828AL, or see if they'd custom grind it as an 1818--the magnum exhaust, especially if you do the cleanup I mentioned, flows 75-80% of the intake, and you don't really need a split duration cam, it just increases overlap.
as it is, IIRC somebody on the board has a magnum 360 that he had the cam reground at bullet (was something like 218@.050 and ~480" lift, IIRC) in an A-body with a 4bbl and is running in the high 12's...
Posted By: patrick
Re: New build: LA or Magnum?? - 07/07/10 01:31 PM
Quote:
Quote:
I would get a 2000-02 magnum if I had the choice but they are all very close. The heads I have recently found out have slightly bigger ports not much but a hair, 5cc on the two sets of later heads I have here. Also they had a slightly better cam, the same cam as the R/Ts originally had, the last couple years they all got that slightly revised cam. You should be able to get a good low miles one for $500-700 and bolt on headers and an RPM air-gap intake and make close to 350 HP. The 300 hp crate motor has made 320-325 on several different dynos when it has good headers, and it had a smaller crappy cam and crappy M1 intake. With a re-ground cam and better springs you could get close to 400hp.
I located a 2002 engine with 51k miles for $1,100 complete and I think it's expensive. Anyways, with that being said here is a couple questions I have.
Should I worry about cracked heads?
When you say R/T Cam what do you exactly mean? I was under the impression that all 360 Magnums after 95 had only .410 valve lift camshafts? Should I just throw on an intake, carb, distributor on a Magnum engine and run with it?
$1100 seems pricey to me. does it include all the accessories? I'd say $700-800 max, I'd see if they'd sell just the long block (minus intake) and let them part out the rest.
there's some argument as far as what the cam specs were, that they may have changed some over the '98-02 time frame...
I was under the impression that the 15HP boost they got (from 230 to 245) in '95 was going to essentially the same exhaust that the SST's had (2.5" muffler to 3" tail, vs. the ~2.25" muffler/tail of the '97-down)
if it runs good, and you pulled the pan and it's clean, I wouldn't be super concerned with cracked heads. IIRC, HotRodDave has seen a number of cracked ones, but none that never actually cause a problem (cracked into the coolant, or caused a burnt valve)
I'd pull the pan, check the rods and main bearings, and if it's good, not even pull the heads...I'd get the cam reground and swap to the hughes valves.
if you do decide to pull the heads, I'd do a little massaging as I suggested in the previous reply...and if you stay below ~.485" lift or so, a cheap valve spring upgrade is to go to your junkyard, and find a couple '94-up GM 3.1 and 3.4L's and pull the springs and retainers off of them.
Posted By: Mr.Yuck
Re: New build: LA or Magnum?? - 07/07/10 01:36 PM
Posted By: OrangeProwler
Re: New build: LA or Magnum?? - 07/07/10 09:13 PM
Thanks again guys. I will keep my eyes out for a deal and Patrick I will be keeping touch. Take care.
Posted By: Prince_Valiant
Re: New build: LA or Magnum?? - 07/09/10 04:13 AM
Quote:
Thanks again guys. I will keep my eyes out for a deal and Patrick I will be keeping touch. Take care.
hate to do it out here...but clean your mailbox steven! I can't PM you!
Posted By: feets
Re: New build: LA or Magnum?? - 07/09/10 05:03 PM
$1100 is stupid money.
Go to a Pick-n-Pull and snatch a 5.9 magnum for a couple hundred bucks. Sell the 340 to one of the people who can't get enough of them and you'll more than pay for the Magnum.
Posted By: DaytonaTurbo
Re: New build: LA or Magnum?? - 07/09/10 06:10 PM
Quote:
$1100 is stupid money.
Go to a Pick-n-Pull and snatch a 5.9 magnum for a couple hundred bucks. Sell the 340 to one of the people who can't get enough of them and you'll more than pay for the Magnum.
A junkyard 5.9 magnum is worth a couple hundred bucks, tops. Sell that 340 for double what you spend on the 360 mag. Your buddy won't have the cool factor of a 340 some guys drool over, but bang for your buck a mag 360 with a cheap reground roller cam and magnum heads will outperform that 340.
Posted By: OrangeProwler
Re: New build: LA or Magnum?? - 07/09/10 06:43 PM
Quote:
$1100 is stupid money.
Go to a Pick-n-Pull and snatch a 5.9 magnum for a couple hundred bucks. Sell the 340 to one of the people who can't get enough of them and you'll more than pay for the Magnum.
Feets I was thinking the same thing. I would tell them to keep the other crap anyways. I was $300-$400 for non rebuilt unit.
Posted By: Andrewh
Re: New build: LA or Magnum?? - 07/09/10 09:41 PM
I think I paid 800 for my 5.9, but that was complete from pan to tb and exhaust manifolds.
I felt a little robbed, but that was also 3 years ago or so.
Personally, yeah, for a low mile one, I would just bolt up an intake, carb and distributer and go. I would leave the magnum serpantine setup as well if you get all the accessories, and run an electric fuel pump.
Posted By: Thackdaddy
Re: New build: LA or Magnum?? - 07/09/10 11:57 PM
Come up to Pick-A-Part in Indy, $169.00 + a $32.00 core charge.
Pick-A-Part
Posted By: gdonovan
Re: New build: LA or Magnum?? - 07/10/10 02:27 AM
Around here $300-$450 complete off craigslist.
Posted By: StandOnIt
Re: New build: LA or Magnum?? - 07/12/10 11:28 AM
I bought a 98' 5.9 with a bad crank for $100.00. Put a 4" crank, eagle rods, Iron Ram heads, Ross pistons and a M1 intake, MP hyd roller .501/.513 camshaft (the 380 hp one I think). Dropped it in a Volare with a stock 904 with a BTE 3800/10" converter and 4.30 rear gear and it went 11.29 at 119 mph. Had a total of about $3500.00 in the motor. Hard to beat that!
Posted By: DusterKrazy
Re: New build: LA or Magnum?? - 07/12/10 04:14 PM
Quote:
Quote:
I would get a magnum short block. Look for 93 and later 360. Reason I'd go short block is the factory heads crack. I think I've seen one set off a take-off engine that weren't cracked. Anyway, get the short block and go either Edelbrock magnums or those new indy cast iron magnum heads. I think there's one other brand out there that's decent. RHS but I don't know where to find their stuff. I really like the eddies though because they have 7/16 studs and you use small chevy rockers. Lots of those around and very reasonably priced.
Magnum R/T heads are another good head but they need work to flow any better than a factory magnum head. At least mine needed work...
Flowed a whopping 210 cfm.
the Indy ones are RHS's hughes sells them starting at $879/pr assembled. the other brand is also austrailian made, Enginequest. Hughes sells theirs as the "Iron Ram" starting at $699/pr assembled.
I have essentially a slightly hopped up 318 magnum ('86 roller cam shortblock, magnum heads) and I'd never go back to LA for a bucks down build. I had my roller cam reground by bullet cams with their HR259/316 lobe, hughes 1110 springs, 2.2L mopar retainers, headers and an RPM air gap (I redrilled the heads to LA intake pattern), and it makes great power everywhere.
What is you're combo with this? Such as rear end gear and transmission setup? I'm thinking this would haul a&^ in an a-body! Which carb?? Fine to reuse roller lifters?
Posted By: patrick
Re: New build: LA or Magnum?? - 07/12/10 05:57 PM
Quote:
Quote:
Quote:
I would get a magnum short block. Look for 93 and later 360. Reason I'd go short block is the factory heads crack. I think I've seen one set off a take-off engine that weren't cracked. Anyway, get the short block and go either Edelbrock magnums or those new indy cast iron magnum heads. I think there's one other brand out there that's decent. RHS but I don't know where to find their stuff. I really like the eddies though because they have 7/16 studs and you use small chevy rockers. Lots of those around and very reasonably priced.
Magnum R/T heads are another good head but they need work to flow any better than a factory magnum head. At least mine needed work...
Flowed a whopping 210 cfm.
the Indy ones are RHS's hughes sells them starting at $879/pr assembled. the other brand is also austrailian made, Enginequest. Hughes sells theirs as the "Iron Ram" starting at $699/pr assembled.
I have essentially a slightly hopped up 318 magnum ('86 roller cam shortblock, magnum heads) and I'd never go back to LA for a bucks down build. I had my roller cam reground by bullet cams with their HR259/316 lobe, hughes 1110 springs, 2.2L mopar retainers, headers and an RPM air gap (I redrilled the heads to LA intake pattern), and it makes great power everywhere.
What is you're combo with this? Such as rear end gear and transmission setup? I'm thinking this would haul a&^ in an a-body! Which carb?? Fine to reuse roller lifters?
3.55's, 27" tall tires, 42RH (A500 tranny), eddie 1406 carb (had to lean it out a bit). it's in my 5th ave, which weighed 3950lbs without me. it keeps up with a stock 5.7L AWD LX car from a roll. yes, I reused some used magnum lifters.
guys have done similar combos (but with EFI) in dakotas and been in the 13's....
in mixed driving I'm getting 17-19mpg to boot.
Posted By: DusterKrazy
Re: New build: LA or Magnum?? - 07/12/10 06:08 PM
Tell me more about 42RH? is it a lockup or overdrive trans??
Posted By: patrick
Re: New build: LA or Magnum?? - 07/12/10 08:25 PM
42RH is the alpha-numeric designation of the A500 (46RH is an A518)
the front half is a low gear A904 (well, 998 actually), with 5 disc front clutch, and 2.74/1.54 1st & 2nd gear. the tailshaft area has another planetary (it's actually a 727 planetary from what I've read), that provides a .69:1 OD. it's also a lockup tranny. in OD it cuts my cruise RPM to be like I had 2.45's out back.
Posted By: DusterKrazy
Re: New build: LA or Magnum?? - 07/12/10 08:30 PM
Quote:
42RH is the alpha-numeric designation of the A500 (46RH is an A518)
the front half is a low gear A904 (well, 998 actually), with 5 disc front clutch, and 2.74/1.54 1st & 2nd gear. the tailshaft area has another planetary (it's actually a 727 planetary from what I've read), that provides a .69:1 OD. it's also a lockup tranny. in OD it cuts my cruise RPM to be like I had 2.45's out back. [/quote
Are they what came in the 80's m bodies? How do you identify them?
Posted By: patrick
Re: New build: LA or Magnum?? - 07/13/10 02:09 AM
nope, came in trucks and vans starting in '88. mine's out of a '93 dakota. I had to mod the tranny mount xmember to fit in my M
Posted By: DusterKrazy
Re: New build: LA or Magnum?? - 07/13/10 03:00 AM
Quote:
nope, came in trucks and vans starting in '88. mine's out of a '93 dakota. I had to mod the tranny mount xmember to fit in my M
Any difference in length?
Posted By: patrick
Re: New build: LA or Magnum?? - 07/13/10 11:43 AM
Quote:
Quote:
nope, came in trucks and vans starting in '88. mine's out of a '93 dakota. I had to mod the tranny mount xmember to fit in my M
Any difference in length?
yup, I had to have my driveshaft shortened about 4" IIRC.
the OD trannies will fit in an E and '71 up B with some trimming on the case and fabbing up a tranny mount xmember.
older B's and A's you need to hack up the t-bar crossmember.