Thanks Transman, I have been thinking about this.
What kind of compression or boost were you running with the spacer plate ?
Had numerous old Super Stock motors that came in that had the old TRW/DirectConnection 12.5 - 1 pistons that guys wanted to run on the street without anything but a smaller cam. Took the rollers out, rebuilt the motors and added the shim with gaskets.
Didn’t have any problems from any of them. You would have to use a compression calculator to figure out what actual ratio they ran at.
We did use the shim on a motor that was whacked way too much but was used in MP at 12.5 to 1 with no issues either.