Tony the pics in John's book don't really show the dome well. They actually had a dome over the entire top of the piston. The domes were cut quite deeply to accomodate the splayed valve angles. I purchased a new never run set of standard bore pistons from Yunick some years ago. I gave up on putting the engine together because I felt there were better choices out there for the cost. Most of the obstacles can be overcome, you can have a camshaft custom ground, have a custom set of headers built, clearance the lifter bores for the pushrods angles, gaskets can be made, a sheet metal intake can be fabricated and you can use the standard 302 crossram lid.
A splayed valve head is still available from GM, but no hardware for the valve train is offered. Moroso makes a valve cover for the head.
Back to the pistons, I sold them a few years ago, still unused. The only picutre I still have of them has one of them out of the box and turned sideways and you can see the intake relief cut into the dome extends almost all the way down to the top compression ring groove. Someone at Smokey's shop had written some numbers and letters in marker on the pistons, but I couldn't tell where it meant anything really.
The book Camaro Untold Secrets has a little better picture on page 122 of the dome of the piston part number 3865534. The engine isn't really a true hemi, but rather a modified semi hemispherical design as the book states, closer to the big block Chevy. But it is an interesting experiment.
By the way the pistons I purchased a set of the standard 302 pistons from Yunicks that were very heavy modified, with a lot of material removed to lighten them. The "hemi" pistons probably weren't modified but due to the age and oxidation you wouldn't be able to easily tell. Smokey apparently liked to mill a lot of material from the piston including the skirt and balance pad areas below the pin bore and the 302 had a very low pin location to begin with. He also had cut the valve reliefs deeper to allow for additional lift camshafts, he liked to use higher ratio rockers like the 1.7:1s from what I've read. The "hemi pistons" didn't appear to be reworked in this area.
I've never bothered to set up a site to post pics from, but if someone here has the ability to post pics and is interested I can send a copy of the pic of the pistons, but I think the Camaro Untold Secrets book has a better picture and it's highly recomended reading.
[ 01-26-2005, 08:22 PM: Message edited by: SY1 ]