88 305 heads are the same as 92 350 heads correct? Both are TPI.

 

No their not the same. 350 L98 heads have 64 cc chambers and 1.94 (I believe) valves. The 305 lb9 heads have 58c chambers and smaller valves(dont remember the sizes).

 

Crap.
If I throw the LB9 heads on a 350 what kind of problems will I have? Will I have at least the same butt power as an LB9 with 305 heads?
One more option - If I throw 350 heads, casting 14102193 1.94"/1.5" on a 305 what problems will I have?

 

Only problem with 305 heads on the 350 is that itll choke it. As for the 350 heads on the 305, you should be ok with the 1.94 valves... any biffer and you would run into clearance issues.

 

Choke it noticeably to the point where I'm gonna be disappointed?

 

get a little port work done on them and youll be fine. the 58cc combustion chamber (same as vette aluminum heads) is going to up your compression ratio and will give you more power. If you were to go down to your local machine shop they shoule be able to port em out for you if you want, but if you dont I doubt it will cost you much horsepower. I dont think it will choke it bad at all.

 

It won't choke the 350 that bad. The 305 heads use 1.84/1.50 valves while the 350 head uses 1.94/1.50 valves. Not a huge difference. The intake runner volume is slightly more on the 350 heads but the 305 heads can be helped with a quick port and polish. Factory castings can usually be improved on quite a bit.

 

Without a good amount of port work, youll be disapointed with ANY stock casting.

 

I'm back to toying with this idea.
Can I fit 1.94 valves in 305 heads? I'm looking to put in a 350 bored 40 over with flat top pistons. I'm shooting for a compression ratio between 10 and 11:1.

 

Yes.