Anybody ever put 3500 heads on a 3.4

[Lilchief]

I ve seen alot of 3500 top end on a 3400 but not a 3.4 (camaro/bird). Can it be done? How about using a solid lift cam with it. What problems would I run into? The only major change that I know of is changing the pistons and ECM

[SappySE107]

Not sure if it has been done but it could be. Its no different than the 3400 top end swap other than a few things you probably have to mod for anyway. Use the 3400 fuel rail so its not returnless, plug the heads where the coolant temp sensor is, and drill the lower for a 3 wire. Or do it any other way so long as you have it plugged up and plugged in Leave the pistons and change the computer High compression is your friend with tuning. 3500 will actually be lower compression than 3400 heads.

Solid cam would require adjustable studs, and you have to modify the heads to put the pushrod guides on. Its a pain in the ass but can be done (I am doing it for a customer).

ECM is your biggest issue no matter what.

[Lilchief]

Right now I'm running 9.8 cr with ci heads. Heads are really holding me bad. With AL heads my cr would be around 12-13+ cr. Does the 3500 head flow more than the 3400. I was told 3400 heads were just short of flowing 300 cfm after mods. Right now I'm running eagle 6" rods and ross pistons in my 3.4.

[SappySE107]

300cfm? No, not really. The flowsheets are on the site here under pushrods on the left side menu. 3500 outflows 3400 stock vs stock.

[Lilchief]

More like 295? One of the 3400 venders sells these and I think they are stage 1 or 2 heads. My engine builder modifies them and flows everyone he modifies before he sends it to them. I thought that was quite amazing, gaining 70+ cfm from stock. That's almost twice the flow of a ci head, 73% more to be more precise. Well that's all for now. Chat later

[SappySE107]

I have never seen 295 cfm from a 3400 head. I would like to know what size cylinder is used on the flowbench and if it is 28" water depression. Also, what lift would that be?

[torq455]

can you even hog the 3400 heads out enough for that kinda flow?! i've seen some 454's that don't need that much to have great power.

[Lilchief]

Well I stopped by engine builder thursday to drop off some parts for my 408. I asked about the cylinder size,28"water and lift. I was told cylinders were stock size, flow was done with 28" of water and max flow was between .500 &.600. I looked at some sb heads that flow over 300cfm right out of the box,these were racing heads and bb heads over 400 cfm. When I get done with my truck motor I'll go back to my 3.4 and see what I can get done and some numbers.