This summer I over heated real bad and was going to pull the heads and do my planned aluminum head upgrade on my little 305. I go on real long road trips with my car I don't want a crack to manafest its self while several hundred miles away from home.
Now I found a nice set of aluminum L98 vette heads, but the heads I found just happen to be up graded to 2.02/1.60 inch valves.
I don't know if they would work on a 305 with the bigger valves.
Does any one know if a 305 can take these heads with 2.02/1.60 inch valves?

 

Well, a 305 is: 305 = 3.736" bore. So, add 2.02 and 1.60 you get 3.62 inches of valve total, not to mention the valves are not exactly touching and they are off set, not centered, so no, they should not work.

 

Would I be any better off with standard 1.94/1.50 valve heads then?
Oh and my block is bored .020'' or .025'' over. I didn't realize it would be so close.

 

I see them usually go with a 1.84 intake valve, but you might be ok, you need to measure everything to find out.

 

Been awhile, and I haven't searched for it, but a member posted a picture of a 2.02/1.60 head mounted on an empty 305 stock-bore block looking up the cylinder from the crankcase. The valves cleared fine up to something like .550" lift.

How effective those big valves would be is a different matter. The outer edge will be shrouded by the 305 cylinder wall, reducing flow. In addition, it is pretty well established that 2.02 valves are worthless in aluminum Vette heads. If you haven't bought those heads, don't. If you can get them for free, they would be better than no heads.

Don't forget that 58cc aluminum heads are equal to 64cc cast iron heads due to heat loss through the aluminum. Your static compression ratio might remain the same as stock, but the effective compression ratio will be reduced. Shaving them down to 52cc would restore your effective compression.

 

The factory used 1.84/1.50" valves in 305's. A common upgrade is to use 1.94" intake, and some will also install 1.60" exhaust valves. 1.94/1.50" typically work well on a warmed-up 305.

 

Can you elaborate on this a little more? What is meant by that? Why are they worthless?

 

Because intake valves larger than 2.00 don't improve flow regardless with these heads. And, over 1.94" intakes require very careful porting to realize any improvement.

 

Yep. The chambers on the Corvette heads are too small for the valves - they will physically fit, but the clearance between the valve and the side of the chamber is so close that no significant airflow gets past. Thats why the 1.94 valves are better on those particular heads.