Author Topic: 340 rebuild (Read 7409 times)

Nate70 · « **Reply #15 on:** January 10, 2008 - 06:21:41 PM »

and these two heads sre they aluminum?

http://chucker54.stores.yahoo.net/edcyhe.html

and the difference between the performer 340 and performer rpm is?

go-fish · « **Reply #16 on:** January 10, 2008 - 06:22:51 PM »

No the Edelrock heads are just like the stock ones except with revised intake and exhaust runners, they're lighter and dissipate heat. The biggest benefit in my eyes is the closed chamber design.

go-fish · « **Reply #17 on:** January 10, 2008 - 06:27:49 PM »

There is a Performer head out there that is designed for your 340. I forgot about them, thought they were dicontinued because the regular Performers work fine on 340's too. If they are still available gt them.
The chamber size is different and 340's were higher compression and these Performer 340 heads I believe, don't quote me, are more similar to X heads.
This is why you need to call a shop like Hughes, they can give you the straight poop.

Nate70 · « **Reply #18 on:** January 10, 2008 - 06:28:59 PM »

what about changing intake and headers if I go aluminum heads do I need to change them?

go-fish · « **Reply #19 on:** January 10, 2008 - 06:33:33 PM »

No, none of that stuff needs to change. However if you get another cam you may want to see if there is an intake that works better for that particular cam, i.e. sigle plane, dual plane, etc.

go-fish · « **Reply #20 on:** January 10, 2008 - 06:38:11 PM »

What kind of driving do you do. If you do alot of in town driving with rpm's in the 1000- 4000 rpm range you would be well off with what you have for intakes. If you want to make alot of power up high like 2800-5500 rpm you would ant to go with a single plane. You will probably be better off just keeping your intake since you aren't tryin to chase people down on the big end of the 1/4 mile.

go-fish · « **Reply #21 on:** January 10, 2008 - 06:43:31 PM »

Hey Nate, I just read your introduction post. I'm a CM2. I'm leaving for Bahrain in about a month.

74 340 4speed · « **Reply #22 on:** January 10, 2008 - 06:43:46 PM »

Mopar performance has released these new commando heads:

This is the only image I could find. It shows a bare head, but every description I've read on the heads states that they are assembled.

�Commando� Standard Port Cylinder Head Assembly
2.02" Intake Valves, 1.60" Exhaust Valves. High-Performance Valve Springs � up to .535" lift. Chrome Moly Retainers. Valve Spring Seat/Cup. Fits all 1967�1991 318, 340 and 360 �LA� small block applications and current Mopar R3 blocks. Uses production shaft-mounted valve gear (oil through the head) or Mopar Cast Iron Ductile Rocker Arm Package P4529738 and On-Center Rocker Shafts P4510636. The �Commando� Standard-Port Cylinder Head also retains the production exhaust flange pattern and stock 340/360 �LA� intake manifolds.
5153535 �Commando� Standard Port Cylinder Head Assembly

The cheapest place I found them was http://www.newdodgeparts.com. They were $1,087.20 per head. I haven't seen the flow numbers for these heads yet. Until more information is available, you would probably be better off with the edelbrock heads.

go-fish · « **Reply #23 on:** January 10, 2008 - 06:51:37 PM »

That's a good deal, if they are available. Still would have them checked over before putting them on.

go-fish · « **Reply #24 on:** January 10, 2008 - 06:54:02 PM »

After looking again, those Commandos would put you at over $2K and you don't have the weight savings and heat dissipation of aluminum.

74 340 4speed · « **Reply #25 on:** January 11, 2008 - 01:05:41 PM »

I thought the commando heads were aluminum?

That's what is on the new 440 Commando small block.

440 SUPER COMMANDO CRATE ENGINE � 540 HORSEPOWER (EST.), 550 FT.-LBS. TORQUE (EST.)
Big block power and cubic inches in a small block package! Mopar�s new 440 Super Commando small block stroker crate engine gives you over 500 horsepower on pump gas, and offers the compact size of a small block.

Specifications:
Bore: 4.180" Stroke: 4.000"
Compression Ratio: 10.2:1 (Est.)
Block: New 340 Siamese Block with 4-Bolt Mains
Cylinder Heads: Aluminum
Intake Manifold: Mopar M1 Single Plane
Camshaft: Hydraulic High-Performance � 251�/257� Duration @ .050", .603" Lift
Oil Pan: 8-Quart Center Sump Street/Strip Oil Pan
Crankshaft: Forged 4340
Pistons: Forged
Valves: 2.055"/1.600" Stainless
Connecting Rods: Forged 6.123"
Rocker Arm: Aluminum Roller w/ 1.6:1 Ratio
Note: Shown with available carburetor and air cleaner assembly.

Jacksboys · « **Reply #26 on:** January 11, 2008 - 01:38:17 PM »

Hey Nate70,
I built my 360 last year to about the specs you are looking for so here is some information for you.

If you are looking for the Edelbrock aluminum RPM heads, you should go with the closed chambered 63cc version (#60779) and then run a flattop piston that is level with the top of the block. You will also need the preflatten felpro head gaskets for these. I am not sure of the exact piston, so do a little searching and ask others on here. The complete heads are $679.50 each at summitracing.

The Voodoo cam you are suggesting would be a good match. (I used the Comp Cam Extreme version with slightly less lift) You should be able to use all of the stock valve train, but I would still check the valve-to-piston clearance to be certain.

Then get the Edelbrock RPM intake and a carb in the 600 to 700 range. I would suggest using the vacuum secondary version, but it is your choice. You should not have any problems with your (R/T) hood clearance if you use a drop air filter; just double check it before you slam the hood the first time.

I would then suggest a torque converter with at least a 2000-rpm stall. Also I would suggest at least 3.23 gears or numerically higher depending on where you drive it the most. Plus a suregrip would help with traction (Mine is still open

).

I went the cheap route with headers and got the hedman versions, but if you want a good header, TTI is suppose to be the best, but they are not cheap.

I hope this helps.

go-fish · « **Reply #27 on:** January 11, 2008 - 02:59:29 PM »

I believe the first rendition of the Comando head was iron. Not sure, I could be wrong. Still, how would they compare in price to the $680 Eddy's? Also, be certain that anything from Mopar Performance aside from intakes will need to be thoroughly checked before installation because parts are often rough. Edelbrock has tighter tolerances and their fitment is usually the best of any aftermarket part. I, personally, would go with Edelbrock based on that. MP is notoriously bad about parts availability and quality issues. Half of the stinkin' items in MP catalogs aren't even available.

Chryco Psycho · « **Reply #28 on:** January 11, 2008 - 03:59:05 PM »

the 340 performer head has a relief inside the head as the true 340 pison was .010 above the block & would be too close to the head without the relief ,, the set I looked at had horrible core shift though & I refused to buy them

go-fish · « **Reply #29 on:** January 11, 2008 - 04:18:10 PM »

Cryco, what do you think of the quality and availability of MP stuff?

Author Topic: 340 rebuild (Read 7409 times)

Nate70

Re: 340 rebuild

go-fish

Re: 340 rebuild

go-fish

Re: 340 rebuild

Nate70

Re: 340 rebuild

go-fish

Re: 340 rebuild

go-fish

Re: 340 rebuild

go-fish

Re: 340 rebuild

74 340 4speed

Re: 340 rebuild

go-fish

Re: 340 rebuild

go-fish

Re: 340 rebuild

74 340 4speed

Re: 340 rebuild

Jacksboys

Re: 340 rebuild

go-fish

Re: 340 rebuild

Chryco Psycho

Re: 340 rebuild

go-fish

Re: 340 rebuild