Both the the right and left are cast pistons. As for looks all I can think of is a difference in what they may used to finish them with after machining. The one on the left is the same material hypereutetic [sic]. Didn't massage it.

9:1 with a stock 74 CC head. If you unshroud the valves then you would be less than that. I would like to be at about 10.5:1 with a stock head. Then 10 CC change in the head one way or the other will get 1 point change.

The welding idea didn't sound real good to me either. It looks like the only way get a flat top piston is to go forged. I am looking at another cast piston for a GM 366 CI V8. The problem with it is the pin dia. is .9898 compared to the 292 which is .9273 and compression height 2.16 to 2.009. There doesn't look like there is enough meat on the piston end of the to offset the bigger pin. Even if there is it still means milling 80 thou off the top of the piston. Anyone interested in a set of pistons. (I know not here)

I've checked the deck and with the old pistons I'm at .072 and Leo Santucci says don't take off more than .030. I've already figure that into my calculations.

I really don't like going forged form this application, it's basically a street machine. A cast piston should handle the compression with out a problem. These cast pistons were not cheap. I'll check with Keith Black about finish machining the 366 to the 292 spec. If I don't get a NO from K. Black the price will still probably be bite the bullet and order forged.

Larry

Ignorance can be fixed Stupidity is forever