I'm in need of a set of heads for my twin turbo 454. I have found a set of Iron Eagle 345 cc runner heads and wanted to know people's opinions on running these on my engine. My compression ration is 7.5:1 Hydraulic flat tappet turbo spec Comp Cam. Spinning this to about 5400-5600. The turbos are a draw thru system that then goes thru a intercooler. The turbos are rayjay and I plan on pushing it to just under 15 psi of boost.

That's cool.

They should help. I'm geussing there is lots of restriction in other areas too. Canning the intercooler for a single plane and a blow though carb would probably make better power too.

That routing looks torturous with lots of opportunities for fuel to fall out of suspension, especially once it's cooled in the intercooler. Blow through Carburetors are their own intercooler.

Okay I have a question here, since the under side of the carb will see the boost, and the top side atmospheric, what keeps the boost from blowing out of the carb? Carbs work on vacuum or blow through only correct? What am I missing here?

Never mind, I see now that is the intake.....sorry

Yes the exhaust manifolds are probably the biggest restriction TurboJack had the same set up and said that beyond 15 psi of boost, all your doing is superheating the exhaust because the log manifolds cant get the exhaust out. I have looked into converting over to center rise manifolds, but that would require quite a bit of fabrication (unfortunately I do not have easy access to a fab shop) to make the turbo fit next to the intercooler and it would require modifying the exhaust because the turbos would not be inline with the holes in the transom for the tail pipes. Ideally Ill be going to a single plane EFI manifold so that will help with the fuel suspension issue.

Can I ask why the 345's ?

Compressors add air and they also compress it...thus their name. Many times, the runner size (cross sectional area) does not need to change because of this.

My old heads do not have pressed in seats, and a few guides are worn. Instead of spending $1000 on inconel exhaust valves, stainless intake valves, cutting the seats and new guides. Joe at Champion Performance in Warren is not sure that he wont hit the water jacket when he is cutting for the new seats. I found a set of Iron Eagle 345's for sale that have new Inconel valves and about 25 hours of use for a good deal. I figure that a newer set of heads would be better than rebuilding my old heads.

OK the deal on the Iron Eagle 345's fell thru. But I did find a pair of Merlin Grumpy Jenkins 345's for sale. I know most guys put them on 540. Even with my engine being twin turbos, will I just lose all kinds of bottom end?

Exhaust flow is not as critical. It's the exhaust gases tendency to expand due to being hot that drives the turbo. so the smaller volume should help the spool time.

My concern is if a iron head with 345 cc intake runners is too big for a 454 with twin turbos? Currently my engine has 7.5:1 compression The cam is 226/ 218 @ .050 115 LSA turbo grind from Comp Cams. I'm running cast iron log manifolds. The turbos are Rayjay's with wastergates set for 10 psi, but I can go up to 15 psi. The air goes thru an PFM intercooler.