Re: Help identifying these pistons if possible
Looks like a 71 w/Sp. H/Per. (454) standard bore
Is there any code on the front stamp pad?
That is what the pistons are. GM rated the 71 LS6 at 425 hp with the 074 heads. They had app. 118 cc. and the compression ratio was 9 to 1. The 188 will have a couple more cc. I would think your compression will be in the 8.6 -8.8 range.