Thanks - that solves that riddle and indicates that the Montero/Raider 8.9:1 CR heads have the same cams as the SOHC 12v 3000GT/Stealth cars. That suggests that the HP/TQ changes are due to spark timing and intake/exhaust manifold improvements in the car platform.

The Diamante 10:1 SOHC valve timing specs came from here:

web page

Charlie - I'd like to include knock sensing, but I've read that the sensor mounts in the valley and there's no boss provision in that area on the early 6G72 blocks. I guess I could install a sensor somewhere else on the block, but I'd think the OE location might be the best way. Maybe I'll look for a different block and see what can be done.

Frank