Just wondering about fitment I do not have the 601's yet but have access to a pair and before i start playing I want to know if the 91 TPI intake will bolt up or not?

Any other concers I should be worried about?

Car is a 91 LB9 i like the combustion chamer size, but will they be feasible to use later on a 350/383 ?

 

They're pretty similar to your current 081 heads, why swap?

You'll have to elongate your intake manifold bolt holes to use the TPI on your older style cylinder heads, and you'll need perimeter bolt valve covers. Everything else should be fine.
The chambers would most likely be too small for a 350/383, unless you grind them open a bit. They'd need a schwack of porting to be worth using on a bigger engine like that as well.

 

I have them (with bigger valves) on my 350 and they work great. Be careful what pistons and gaskets you use though, its not hard to go too high with the compression with these heads. I'm at about 11.25 right now.

 

I'd just stick with the stock 305 TPI head (081) If you want more hp. port them with larger 1.94" valves. If you want more compression ratio, mill them some and or use a thin shim style head gasket. The power potential of these heads is probabily better than 601's. They fit your car. They have a better chamber shape. They have the center bolt vale covers. A more desireable head.

 

Actually the 601s have the better chamber design compared to the 416/081 heads, but not really enough to make much HP difference from that alone. They do breathe a bit better in stock form though too. The 601s use perimiter bolt valve covers, but thats a very minor change. Leaves more clearance for roller rockers though - you can use any set you want. The 601s were a HD casting too though, they are a little bit beefier cast. Little bit stiffer deck surface and more meat for porting.

 

Adam, have you seen all 3 castings? I've recently seen a pic of 081 heads, and they do look like they have different chambers vs 416's, something I never knew about before. I've only actually seen 416's myself. I'd like to see 416's vs 601 vs 081 side by side to see the diff.

 

I have seen all 3 side by side. The 416 = 081. The 601 has a shape similar to the old fulie heads of the 60s.

 

Which pic is what?
Alright, since you have actually seen, and held all 3, i'll take you at your word. I remember a recent thread where I mentioned that, and someone called me on it, and I didn't have any proof.
https://www.thirdgen.org/forums/engi...?highlight=416
I'm going to post on that thread a link back to this thread.

 

The left picture is the 081 casting which has an identical chamber to the 416. The one on the right is a 601 casting. It actually has some relief work that has been done to this particular set.