Compression ratio

When i built my 2nt 340 i used forged stock pistons (TRW's) i did all the cc of combustion chambers pistons valve reliefs.(two valve reliefs)
my "stock" 10.5 motor was 9.4:1! i check and double checked it with total disbelief.
At the time you had a choice of stock (10.5) piston and dome pistons 11.5 so i got the spec's on the dome piston......they came out to be 11.4...................so a 9.4 compression i had to deal with.......It ran really good with stock X heads.