67 383/325 hp - 68 383/330 hp - 68 383/335 hp Compared

[Bighead440]

I know of a 383 that is .1 unsquare across the deck...machinist must've had a rough weekend when he did that on Monday morning. No piston was going to have a positive deck on that engine.
We have never had a 69 350hp 440 apart and if guys say their 68 was .055 down that is what it should've had according to every rating I have seen. We were quite disappointed to find a 67 piston in the two 68 350hp engines we took apart, they certainly may have not all been that way. Maybe our were earlier 68s? The 70 also uses the 67 piston. In 71 the 440 piston we have looks like a 70 piston but with a dish. By 72 they started being .145 down the deck and a flat top but its been 30 years but I don't remember a dish. In the later 70s I have seen some guys post pictures of a 440 piston .145 with a dish, possibly a rv or industrial piston? I have never run into that...chrysler must have been trying for a military contract for a all fuel engine.Lol

Yes, my '71 Imperial 440 had the dish pistons and I compared them to a '68 piston and they were the same at the edges. The '72-? piston seems to be the same height all across the flat top as the bottom of the dish in the '71s. I think the very last 440s and maybe some motorhomes had even less compression distance than the (advertised) "8.5:1" engines had. A friend had a '76 D300 dually with a 440 and the common cast replacement '72-up pistons were actually taller than the OEMs.