72 barracuda 340 swap

[thesado]

Hello,

Thought I'd share as I swap my mild 318 for the 340 I've always wanted. I've always been a smallblock fan. 

About a decade ago I added an intake, 650 holley, and a purple cam to my stock 318 to get a lil more oomph out of it. It worked, but recently I stumbled upon a good candidate 340 that had my name on it. '69 block from a manual '70 car. Never rebuilt, but with an LD340 intake, AVS carb, 273 rocker arms, no cam, and a burned valve. A few pieces were missing (as I mentioned http://www.cuda-challenger.com/cc/index.php?topic=121447), but I managed to acquire a junked "donor" 318 for some of them.

Goal:
Rebuild to mostly streetable stock, on pump gas, keep the price sane, and add some mild (low hanging fruit) performance where it makes sense (the intake, 650 Holley, and headers).

Cam:
Could re-use the purple cam I have from the 318 build (P4452759), but I'm not settled on that yet.

Valvetrain:
Return to stock.

Heads:
Hardened seats. Considering a light home-shop gasket matching port job.

Pistons:
The The cylinders and pistons are worn enough (about .007) to warrant a bore, so I'll need .020 pistons. I'm currently trying to decide between KB 243 and TRW/Speed Pro 2316. Although I think JE 345778 might still be on my list too, but pricey.

Headers:
Leaning toward Doug or TTI due to a lot of reviews around here. Definitely want coated. Will need to research fit.

Intake:
LD340. Considering a light home-shop gasket matching port job.

Ignition:
I like the idea of a hotter spark and a rev limiter. A FBO HRR688 might be on the list.

Carb:
650 Holly, but if I have any issues with it (doubtful) I can always try out the original Carter AVS.


Some pics attached of the 340 and the disgusting 318 donor with a nest in the bottom. 

[redo1973]

Cool opportunity.

[70chall440]

You make decent power with a mild 340, especially using modern parts such as some of the new heads, roller rockets and cam, good ignition and intake/fuel system and of course good exhaust (TTI).

[thesado]

Tiny update:

Got a call from my local machine shop. They magnafluxed the block and heads. No cracks. Valve springs are about 80lbs, so should be replaced, I'm told. I'll pick up the heads soon and start on the gasket matching and VERY mild port at home. Then will return them to the shop for hardened seats installed.
I decided on the TRW pistons, so they can bore the block soon too.


Speaking of cam and rockers, @70chall440, do you (or others) have any suggestions on a good cam for a 340 build like this? Originally I had intended on using the stock cam, but now I'm thinking I'll aim for a more performant cam that still has good street manners.

[redo1973]

I've done a mild 340 engine build 320-340 HP.  The engine shop suggested a Speed Pro Sealed Power #CS-1019R.  It is 214/224 at .050 CAM lift.  This selection was based on stock exhaust manifold or an upgrade to shorty headers. My research tells me that this is styled like a 1968 CAM for a four speed.  It has a choppy idle and roars pretty good through 2 1/2 TTI exhaust and stainless tips.  I've not had it on the road yet.  The other specs on this decision: 27-28 inch wheels, 3.23 Eaton Tru-trac and a 750 CFM Carb with an Edelbrock Dual Plane performer intake from the 1980's.  There are plenty of others with more expertise on this topic.  You may wish to put the question on Engine Combinations.

[cudamadd]

A nest wow you  can say that again .  Great photo 

[70chall440]

I've done a mild 340 engine build 320-340 HP.  The engine shop suggested a Speed Pro Sealed Power #CS-1019R.  It is 214/224 at .050 CAM lift.  This selection was based on stock exhaust manifold or an upgrade to shorty headers. My research tells me that this is styled like a 1968 CAM for a four speed.  It has a choppy idle and roars pretty good through 2 1/2 TTI exhaust and stainless tips.  I've not had it on the road yet.  The other specs on this decision: 27-28 inch wheels, 3.23 Eaton Tru-trac and a 750 CFM Carb with an Edelbrock Dual Plane performer intake from the 1980's.  There are plenty of others with more expertise on this topic.  You may wish to put the question on Engine Combinations.

Good advice. You might try contacting some of the notable engine builders and asking the question/s. I have found that most of them are more than happy to tell what works and what doesnt. Also, as suggested, post a thread in the engine section and you will get some specific information. All this said, I have had good luck with the Mopar purple cams but I went Crane Roller with my 340.

[thesado]

I've done a mild 340 engine build 320-340 HP...

Actually I just finished reading your Resto Mod 1973 Barracuda round 2 post http://www.cuda-challenger.com/cc/index.php?topic=111075.0. Great project! I was hoping you'd chime in since I saw there that you have the 340 as well. Great info, thank you!

Good advice. You might try contacting some of the notable engine builders and asking the question/s. I have found that most of them are more than happy to tell what works and what doesnt. Also, as suggested, post a thread in the engine section and you will get some specific information. All this said, I have had good luck with the Mopar purple cams but I went Crane Roller with my 340.

Yea, I should post over there. I'm not sure who is a "notable engine builder" to contact. I'm afraid I've been out of the loop for a while.
I've actually been tempted by a roller cam for this build. But I can't decide if it will be "worth" the cost on this build. Honestly at this point I've probably read too much and confused myself. 

[70chall440]

Try Mike at Muscle Motors; pretty much Mopar only guy. You could also try Barton or Keith Black.