Hi wondering what heads would be a good bolt on, what people have experienced that worked good, wondering if those corvette heads with d shaped ports work. Thanks-

Be aware, the heads on these engines aren't the bottleneck. Heads are expensive, i'd wait until you've removed all the other bottlenecks before tackling this.

Yes, the Corvette 113 aluminum heads (if those are the ones you're talking about) are a good bet. You can port your stock heads, they respond well to that. Also, the World S/R torquers are a good replacement head. I think Five7 has used them with success on his 305, and then on the 350 that replaced it.

True statement.

Two things about the Worlds: 1) They need port clean-up - every magazine article I've seen about them included that (hmmm, wonder why); 2) I punched a hole into the coolant passage by using 1" long header bolts. Had used the heads for 4 years with 3/4" long header bolts with no problems.

Well, 3 things: I polished the chambers, not really removing any material or attempting to unshroud the valves or anything. They cc'd at 64cc instead of 58cc.

About the aluminum Corvette heads: They will have the same effect on compression as putting on 64cc heads. Aluminum allows more heat to escape, which lowers efficiency and power, which are regained by raising the static compression ratio. Although they have larger intake valves than stock LG4 heads, don't expect power gains by bolting them on to an LG4.