Join Date: Mar 2007
Location: Fort Worth, Texas
Re: 351w piston question
Well, that means your block is an early casting with a 9.48" deck height. Keep in mind if could have been decked during rebuild and might be slightly shorter.
But more importantly, you need the head casting numbers. They are on the underside of the head. It's this number that will be of most importance determining your current compression ratio. Being a reman engine, just because it has an early block casting, doesn't necessarily mean it has early heads to match. Do you happen to have any pics of the underside of the heads before you installed them or did you write their numbers down perhaps?
Otherwise, the only way to answer your original question is to pull a head and verify it's casting #'s and therefore it's chamber volume. While you've got the head off, you can measure how far down in the cylinder the pistons are at top dead center. Next, you can get some exact measurements on the dish size in your current pistons too. Only then can we accurately determine what compression ratio you truly have right now and if swapping pistons is what you really need to do. Keep in mind that just because a piston or head is advertised to give a certain compression ratio, doesn't mean that's what it actually gives. The only real way to know is to measure.
Also I couldn't find anything on ATF reman engines. Did it perhaps say ATK?
1964 Galaxie 4dr 351W Daily Driver, 1967 Galaxie fastback 460,
1969 Montego MX 410, 2 x 1977 Grand Marquis 460 & 400, 1979 F150 400