I was curious what kind of power a stock set of 601 heads will support.

I have a .030" over 305 TPI with full intake and exhaust, roller rockers and some other mods.

I'm currently not impressed with the way the motor just shuts down at 4500RPM. I believe the rebuild company used the peanut cam.

I want to do a Cam swap but don't want to motor to still die at 4500rpm because the heads are holding everything back.

 

The TPI lays down at around that RPM.

The heads themselves will flow about 375 HP or so, with decent porting; maybe closer to 400. No way TPI will support that though, its "tuned" function defeats any degree of higher RPM operation, thereby limiting HP.

 

I forgot to mention I'm running Re-Tuned Port Injection:

https://www.thirdgen.org/forums/atta...405_131547.jpg
https://www.thirdgen.org/forums/atta...325_202936.jpg


This intake is capable of making power well past 4500 with the right cam.

 

Did you forget the TPI 383 with the 212/218-110 cam Extrude-Honed aluminum L98 heads and extrude-Honed TPI doing 458 HP @ 6200 RPM? Stock TPI is happy to 4800 on a 350. 305 should do 5000 with NO mods. Swirl-port heads and "peanut cam" together do peak around 4000, but I myself have spun that combo to 6200 in first in a stock LO3. That is, admittedly, not TPI, and it was with a worn timing chain and a muffler upgrade, but still, it evidences adequately that even the worst 305 should happily pull well past 4500, suggesting a partly-clogged catalytic converter, or a weak ignition coil, or both, or who-knows-what?

 

It will still pull a little past 4500 just not very strong.

Catalytic converter could be a possibility IF I had one. I'm running an accel supercoil and the distributor still has a JEGS module in it from a P/O.