Back in the 90s, a company called Mega Power designed billet insert, twin heads for the VMAX 4. Not many of those head sets were actually produced and sold but I have a set. They solve any and all sealing issues common to machined stock, weak cast OEM cylinder heads on high compression race engines. I'm considering re-producing these head sets to make them available once again in limited numbers. These heads are amazingly well engineered pieces and I intend to make machinable blank inserts for folks to cut their own chambers, as well as the original race inserts. If there's enough interest, I'll do this. Anyone interested? Performance shops are welcome too.