For cost and performance what heads are the best? High compression is desired, around 10:1 or maybe even higher. Does head CC volume directly affect compression? Like, 9:1 JE pistons with 64cc heads compared to 58cc heads, will the volume affect the compression? Higher compression means more horsepower correct?

 

Your compression ration is actually based on the volume of the chamber. A smaller chamber means more compression which translates into more power. However, you don't want to go more than about 10.5-1 if you plan to run pump gas or you WILL have problems. Pick a good set of heads first, then when you order your pistons tell then the chamber size and compression you want. They'll give you the right piston. Stay away from heads bigger than about 70cc though, as they require domed pistons ($$$$$$$) to get good compression.

 

Yeah TheGreatJ is right go with some afr 190cc (68cc chambered) heads and a new cam to see super results. And yes higher compression can mean more horsepower if done right.

SSXeon

 

The 64 cc head will drop your compression on a 305, but you can negate some of that with a smaller head gasket. The FPP-1094 shim works great, ist only .017" compressed and I think stock is .032".

 

Well I want to find some heads for a 350, 64cc seems to be the standard, I know 305 heads are 58cc, is there any value in having the 305 heads professionally ported and having larger valves put in? This way you have higher compression and comparable flow...or would a good 64cc pair of heads still be better? The motor is looking for 325RWHP, would the 305 heads design not be favorable for good combustion, would a better pair of aftermarket 350 heads make up for a possible loss in compression from higher volume?

I'm just wondering, because why spend 1000$+ on a set of aftermarket 350 heads when I could use 305 heads, put 500$ into them, port them myself, have the valves enlarged (can they be enlarged?) and have them flow to the point where I could hit 325. I know comparing 305 stock heads to aftermarket is useless, but my view is why spend 1200$ on AFR which WOULD flow for up to a 600HP motor, when I could spend half as much to get my 305s reworked to put out 325. Having new more expensive 350 heads that COULD put out 600HP is useless to me, it's money lost that could be spent elsewhere.

I'm just wondering if the overall design of the 305 head is unfavorable for a 350.

Another option is the Vortec heads, they are only 500$ for a complete pair correct? (valves, etc)

They look like they are good for the HP I'm looking for right out of the box with potential to go further. For 500$ they look like a good deal to just "bolt on" and go. Any comments on these as well? They seem like too good a deal considering the price.