Previous Thread
Next Thread
Print Thread
408 LA Street/Strip build #2817759
09/06/20 11:35 AM
09/06/20 11:35 AM
Joined: Jan 2003
Posts: 754
Longview, Texas
marvo451 Offline OP
super stock
marvo451  Offline OP
super stock

Joined: Jan 2003
Posts: 754
Longview, Texas
I’ve got the 408 LA EAGLE Assembly. Now the tough stuff. Please recommend heads, cam and intake. I don’t want to waste money. Indy MA-X, Speedmaster or something else? Specific cam recommendations as well as intake manifold.

Re: 408 LA Street/Strip build [Re: marvo451] #2817860
09/06/20 03:31 PM
09/06/20 03:31 PM
Joined: Jan 2003
Posts: 1,753
Windsor, ON, Canada
D
Diplomat360 Offline
top fuel
Diplomat360  Offline
top fuel
D

Joined: Jan 2003
Posts: 1,753
Windsor, ON, Canada
What sort of street manners are you willing to live with?

Meaning:
1) high stall converter? If so, yeah, you can get something that's pretty well behaved (this will cost though) but there is a very real difference between any high stall converter that flashes into the sweet-spot, and one that's basically done by 3K
- I went from a 2800 "high-stall" street converter to a 9.5" 4K stall, they are not the same converters, and the 9.5" is a very nice unit, but there is no mistaking their street manners

2) street / strip - what's the split? 95% street and 5% strip?

3) hand-in-hand with #2 above, what RPM range are you looking for?

4) finally, given all of the above, what's the chassis this is going into? light/med/heavy vehicle?

Re: 408 LA Street/Strip build [Re: marvo451] #2817922
09/06/20 05:34 PM
09/06/20 05:34 PM
Joined: Jan 2003
Posts: 754
Longview, Texas
marvo451 Offline OP
super stock
marvo451  Offline OP
super stock

Joined: Jan 2003
Posts: 754
Longview, Texas
‘74 Duster. 2800 stall converter and 95/5 street/ strip sounds right. You know an old racer is going to “strip test” the car. 3.55-3.73 gears.

Re: 408 LA Street/Strip build [Re: marvo451] #2818129
09/07/20 11:55 AM
09/07/20 11:55 AM
Joined: Jan 2003
Posts: 1,753
Windsor, ON, Canada
D
Diplomat360 Offline
top fuel
Diplomat360  Offline
top fuel
D

Joined: Jan 2003
Posts: 1,753
Windsor, ON, Canada
OK, so I am in the process of building a 408 W2 based stroker. I'll give you the AS_IS & FUTURE configuration and some justification for what I have picked.

The car is my 1980 Dodge Diplomat Coupe, 3600 lbs (race weight), 4K stall converter, 4.10 SG gearing, the same intended use split as what you have.

1) AS-IS (current combination)
360, 0.020" over, factory heavily ported heads (2.02/1.60 - 291cfm@0.550" Intake, 177cfm@0.550" Exhaust), 10.5:1 static CR, hydraulic flat tappet cam: HE3844AL (Hughes Engines) - 238/244@0.050", .535/.540 lift @ 108 LSA, Performer RPM intake, 1-5/8 primary tube headers (Hooker) into 3" X-pipe exhaust system

2) FUTURE
408, 0.030" over, MP W2 Econo long valve heads (2.02/1.60 - 252cmf@.600" Intake, 200cmf@0.600" Exhaust, stock out-of-the-box numbers, these heads have not been touched yet, they will be ported next), 10.5:1 static CR, hydraulic roller flat tappet cam: XR292HR custom grind (112 LSA vs 110 of catalog cam) - 240/248@0.050", .584/.581 list @ 112 LSA, higher lift due to the 1.6 ratio rocker arms), Edlebrock 2920 Victor W2 (single plane), 1-7/8" primary tube headers (TTI) into 3" X-pipe exhaust system

Alright, so the big driver here was the move to a W2 setup in combination with hydraulic roller cam. Since my intended use is 95% street I picked up the XR292HR cam but ground on 112 LSA to give me slightly better street behaviour. Most of the feedback I got here on that choice was that I am giving up power and something like 108 LSA would be a better choice. Given that I am going from a Performer RPM (dual plane) intake to a fairly stout single plane I figured it made sense to do a 112 LSA.

I already have a nice 4K stall converter. Previously I was running a 2800 and with my HE3844AL cam that simply wasn't enough, the car was slow to pick up. Moving to the 4K stall was literaly a day&night type of a change, this put the combination right into the "sweet spot", or at least that's my perception. Originally I was running a 3.91 gear, then moved to 4.10 a couple of years ago. This was not a significant change, but the ol' "butt meter" did certainly register. Seemed like a move in the right direction because the overall combo felt like it finally came together.

Now, moving to a 408 stroker I figured I could take a chance on a dual to single-plane intake switch. The 112 LSA should support that further given that I need to run power brakes as well and currently pull about 7-8" of vacum @ 800 RPM with the HE3844AL cam, so brakes are alright at that level, no issues, but I am using a dual-tandem brake booster (which helps).

Given what you have, 2800 converter and 3.55-3.73 gearing, I would say stay below the 234@0.050" cam duration. If at all possible go roller route since that just makes sense given the on-going zinc/oil-mix changes. Lunati seems to have some pretty nice cams, something like the Voodo Retro-Fit #20200712 (60412), 2200 - 6200 RPM range, .535"/.550" lift with 231/239@0.050" and 282/290 advertised on 110/106 LSA/ICL. Their catalog description reads:

"High performance street cam. Likes up-graded intake, carb and exhaust. Needs 2800 RPM stall converter in most cases. Requires 9.5:1 compression."

Here is another one from Herbert Cams, I love the lift on these and will probably go that route if I end up not liking the XR292HR cam: CEH3, 2200-6000 RPM range, .525/.525 lift with 225/225 @0.050" duration on 110 LSA. Their catalog description reads:

"Intendedfor street/strip applications. 2500+ stall or manualRecommended."

They show some interesting grinds right HERE, but the pros on our site here can better interpret the suitability of the options than I...LOL!

I probably would not go much bigger than that though.

Re: 408 LA Street/Strip build [Re: Diplomat360] #2818268
09/07/20 06:52 PM
09/07/20 06:52 PM
Joined: Jan 2003
Posts: 754
Longview, Texas
marvo451 Offline OP
super stock
marvo451  Offline OP
super stock

Joined: Jan 2003
Posts: 754
Longview, Texas
My biggest concern is picking the correct heads. Now I have several choices that will dictate the rest of the build.

Re: 408 LA Street/Strip build [Re: marvo451] #2818473
09/08/20 10:32 AM
09/08/20 10:32 AM
Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
tubtar Offline
master
tubtar  Offline
master

Joined: Nov 2009
Posts: 3,082
St. Paul , Mn.
Bruce Toth sells an import casting that he gasket matches , pocket ports and fills with decent valves , springs , keepers etc.
1800 shipped.
I haven't run them yet , but did pop a couple valves and looked them over.
I think they'll work O.K. for my 408 , which is pretty similar you yours.
http://www.1962to1965mopar.ornocar.com/toth-mopar-heads.html

Re: 408 LA Street/Strip build [Re: tubtar] #2818510
09/08/20 12:21 PM
09/08/20 12:21 PM
Joined: Oct 2004
Posts: 2,799
Connecticut
FurryStump Offline
master
FurryStump  Offline
master

Joined: Oct 2004
Posts: 2,799
Connecticut
Is that a cast Eagle crank? Small Block strokers quickly out flow most Stock cast style small block heads. If it were mine, I would put a high flow aluminum cylinder head on it. Trick Flow comes to mind. You can go the “w” head route, which definitely flow really well, but they need matching “w” intake and exhaust pieces IIRC. The point being a high flow head gives you room to grow, which usually happens. This stuff is addictive!


best of 11.39 at 117 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]
Re: 408 LA Street/Strip build [Re: FurryStump] #2818536
09/08/20 01:26 PM
09/08/20 01:26 PM
Joined: Jan 2003
Posts: 754
Longview, Texas
marvo451 Offline OP
super stock
marvo451  Offline OP
super stock

Joined: Jan 2003
Posts: 754
Longview, Texas
Does anyone if the Indy MA-X heads for LA and magnum are the same basic castings except for rocker arm attachment and valve cover bolts?

Re: 408 LA Street/Strip build [Re: marvo451] #2818603
09/08/20 03:33 PM
09/08/20 03:33 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
Originally Posted by marvo451
Does anyone if the Indy MA-X heads for LA and magnum are the same basic castings except for rocker arm attachment and valve cover bolts?


I dont know for fact but I would think the ports are the same and I would think the height
of them are the same
wave

Re: 408 LA Street/Strip build [Re: Diplomat360] #2953598
08/13/21 10:37 PM
08/13/21 10:37 PM
Joined: Jan 2003
Posts: 9,146
Now - Port Orange,Fla. Former...
MIKES_DUSTER Offline
master
MIKES_DUSTER  Offline
master

Joined: Jan 2003
Posts: 9,146
Now - Port Orange,Fla. Former...
I’m curious what your car runs the way it is, with the 360???

Re: 408 LA Street/Strip build [Re: MIKES_DUSTER] #2953640
08/14/21 06:35 AM
08/14/21 06:35 AM
Joined: Jan 2021
Posts: 948
rust belt
M
Moparite Offline
super stock
Moparite  Offline
super stock
M

Joined: Jan 2021
Posts: 948
rust belt
Is this going to be a carb or efi?
Quote
Does anyone if the Indy MA-X heads for LA and magnum are the same basic castings except for rocker arm attachment and valve cover bolts?

You can get them in the "magnun" style or with the LA intake style.
http://www.indyheads.com/images/maxlaxnewproductlinK.pdf

Re: 408 LA Street/Strip build [Re: MIKES_DUSTER] #2953648
08/14/21 07:24 AM
08/14/21 07:24 AM
Joined: Oct 2015
Posts: 570
UK
rb446 Offline
mopar
rb446  Offline
mopar

Joined: Oct 2015
Posts: 570
UK
We got a guy here in UK runs a street/strip Demon in our NSS brkt class with a mild 416, has stock 340/360 J heads just cleaned up, probably not even 10:1CR, a mild hyd.flat tappet cam (unkown spec) it only pulls to around 5600. An Airgap intake and a 750DP, ran 11.6>7's with 3.55's and it has a 3500 stall converter, now runs 11.50's with 3.91's@115mph best, the car went slower with 4.10's. The motor makes 410fwhp. That will give you an idea of what is possible with those heads and a mild type hyd. cam.

Plenty of choices out there for ally heads, Speedmasters from what I've read on "A bodies only" have some issues, depends on how much work you can do to check/fix to make them right, only bolt on head is the TF190. I would stay with iron heads for a 95% street car to keep the heat in the c/chamber, your 2800 stall needs a relatively mild cam, prob around 230@.050 or so?. I've only run 340's/440 stock stroke motors so giving specs for your type combo is not in my thought process unless you wanted to make well over 500hp and rev it to 7k with a 5k stall.




Last edited by rb446; 08/14/21 09:03 AM.

1969 'Cuda 446ci, best 9.96@133.9 in 1990
1971 340 'Cuda, best 11.01@122.8 in 1987






Powered by UBB.threads™ PHP Forum Software 7.7.1