my 454 is pulling 180 psi of compression.the engine builder that sold me the pistons said they were about 9.2-1.this seems a little high for just 9.2-1 pistons.the pistons have a .210 dome and the heads are a 781 casting.maybe some of you big block junkies can figure this out for me.the engine builder said this head was one of the better big block castings they made.this s.o.b. pulls hard and has that roar that only a big block has and i believe ,that i'm up around 10-1 to 11-1 compression.tell me what you know

 

It is pretty difficult to determine the compression ratio by taking a compression reading, a lot depends on the duration and overlap of the camshaft. The milder the cam the higher the compression reading will be & vice versa. The only sure way to tell is to physically measure he volume of the cylinder and the combustion chamber. If it runs good, don't worry about it.