rcpilot

Building a NASA CMC(Camaro Mustang Challenge) 3rd Gen... have to run a 305 and I'm going with the "Spec" setup...Holley 4776, Performer mani and cam kit... I need heads for this motor, what heads are the best for the carb setup, I was told the "081's" and the "416's" were TPI heads and they would not flow well w/carb setup. I really need the cast numbers if you have them...

Thanks folks.....

RB83L69

Either of those heads will work fine. In point of fact, both of those castings were used on LG4s and L69s, as well as TPI. Not that the induction system has anything to do with whether the heads are suitable or not.

rcpilot

Thats what I thought, I was told to steer away from "Swirl Port" heads, so I did'nt know if those were swirls or not... I also noticed the "061's" were the same valve/cc's as the "461's".

Joel07

iTrader: (1)

Been a while since I messed with 305 heads, but IIRC, the 434 and 416 heads were the carb'd heads with the 4 perimeter bolt valve covers (not centerbolt). I think the 416's had slightly bigger valves, but they were otherwise identical from the factory. I was running 434's on my 305 circle track car, but we were limited to a 1.76" intake valve, where the 416's had 1.84's.

Again, this is just going from memory, I could be wrong on this. But I'm pretty sure those two are the best flowing of the factory 305 heads.

Good luck with the CMC build, I'm getting ready to build one up myself, so I need to do some more research of my own!!!

rcpilot

Joel... thanks for the info... my brother is running a Mustang and I'm building the Camaro... strange team concept here.. There are only a few folks out west here running the "Spec" setup.. I'm very familiar with the Holley's thats why I'm going carb.. of course everyone is tryin gto get me to go TPI... but after watching the same TPI car die 3 races in a row with computer/module problems I like the carb approach...the TPI's are strong but they do have their probs...:

RB83L69

The 434s were the old 305 2-barrel head from the late 70s. My 78 El Camino 305 2-barrel (120 HP or some such..... very very weak) has those.

The advice about swirlies is good; you definitely don't want those.

The 416 has the advantage of the early-model intake bolt setup. On the other hand it has perimeter valve cover bolts, which are more prone to leakage than the later style that the 081 has.

Other than that, they're pretty similar.

Joel07

iTrader: (1)

Those are my feelings exactly, and why I decided to go the carb'd route. Keep it simple, stupid! is my principle to go by, and for me it's a whole lot easier troubleshooting a carb than a TPI. Too much to go wrong on race day.

I'll be tearing down a 305 that I've got here very soon, it's got the centerbolt heads, not sure what casting #, when I tear them down and check them out, I'll let ya know what I find. It came out of a TBI Caprice, so I'm not sure if it'll have the swirl ports or not.

five7kid

iTrader: (14)

It will.

Joel07

iTrader: (1)

So then what did the 081's come on? 87+ Carb'd cars? I'm gonna guess that those'll be hard to find NOT cracked...

RB83L69

081s came on 87-up carbed and TPI cars.

Anything TBI, you don't want. They'll be swirlies. Guaranteed losers.

Sonix

iTrader: (1)

601's and 461's are the pre '87 305 heads. They're good to use as well.
Surprised no one else mentioned this yet, look up sitting bull, he redid a set of 601s, and had a thread with something like 300 replies (you'll find it...), and it mentions a lot of this info...

Joel07

iTrader: (1)

I think you mean 416's. 461's are the double hump 327 hi-po heads. Also 434's were used for the early 305's.

Joel07

iTrader: (1)

https://www.thirdgen.org/techbb2/sho...=601+305+heads

There's the thread on the 601's. One word of caution from someone who runs a machine shop though. Watch out for those 601's, as they are VERY bad about cracking. Get them checked and hot-tanked BEFORE you do any work to them. I've seen people do all that porting and polishing work, and then find out when they go to get the valve job done that the heads are cracked.

This really goes for any of the later 305 heads, they are thin-wall light-weight castings, and crack very easily. The only ones that aren't light-weight castings are the 434's, and they have the smaller 1.76" intake valves.