i picked up a 350 4 bolt main the other day for $700 its getting swapped is like the next week or so. for right now its going to stay the stock bore but what i wanted to know is should i used the bone stock 350 heads (casting number unknown right now) or should i use the 305 heads that have the port and polish? now i think the 305 heads are 58cc (the 305 heads are off a L69 305 HO) but what i don't know is what the differents in the valve size and all that. what i'm doing just for right now is makeing the 350 run the best that i can with what i have. if the cam in the 305 is still useable then we are goign to use it... if not then its goign to stay stock. so far the mods are going to be a MSD 6A box, a Rev kit, the PRM intake, the headers, jetting the carb, during the winter i'm going to take it all out and bore it .030 over put a forced crank and all that BS. i'm just worried that if i go from a modded 305 to a stock 350 that my 1/4 mile time isn't going to do what the 305 did. if the 350 is slower then that i'm going to be pissed. so do you think it would be wise to use the 305 or 350 heads? give me all your idea's thanks :-D

PS the 305 ran a 15.1 it would run it all day long.

 

All depends on which "stock head" you are starting with for the 350.

If they are 76cc heads then I'd lean towards using the 305 heads
with the smaller 58cc chambers.
This will get the compression ratio up.

You should install larger 350 sized valves in them thou.
Stock 305 HO heads have 1.84 x1.50" valves.
Many people think the 305HO heads have small(er) ports.
The actual ports are essentually the same.

I like using 1.94 x1.60 valves in those heads for a 350 with lots of porting.
If your stock heads are in fact 64cc heads then use them.
They'll respond nicely to porting too.

You can identify your heads by the casting number
and looking them up here

Wouldn't bother using the cam over again unless it is in real good condition.
A budget cam and lifter set from such sources as Summit Racing

or Competition Products Will give a lot of performance "bang for the buck"