I've got a Vortec 350 2 bolt main from a '98 K1500. I've got it down at the machine shop now getting ready for a .030" bore. I've been checking on piston prices and it seems that the cast suggested replacement pistons (4.030") for this are about $30 a piece. I am trying to figure out if I can use another piston that's cheaper. I just want to do a stock rebuild, and I'm going to use the stock ECM and fuel injection as well. I've checked into pistons from Sealed Power (HP815P30)and they've got metric sized rings (2-1.50mm and 1-3.00mm ring grooves). They also have a recessed head .100" x 2.75." with 4 valve reliefs. Are they expensive because of the metric sized rings. The rings are more expensive than regular 1/16" as well. I can't see why I couldn't put another piston in this engine that makes the same compression and let the good times roll. (stock heads, block not decked, heads not shaved, all stock dimensions except 0.030" over bore) Any suggestions or concerns? Also, I've seen compression specs on this engine that range from 9.1 to 9.4? Does anybody know where I can find the compression ratio at?
Well it looks like I just figured my own problem out. After some digging into the Sealed Power book, I found out they make a set of pistons just like the stock H815P30 but have regular size rings. My machine shop can get for about $13 I can't remember the number off hand but its something like HR834P30.
