Originally Posted By bschargerse
Originally Posted By JohnRR
Originally Posted By WO23Coronet
What's wrong with KB162 pistons? Never used them just curious


They are too far down in the hole and have a HUGE valve canyon , err , valve relief. If you don't have a head with close to 80cc chamber and deck the block to bring them up in the bore you end up with less than 9.0 compression.

By the time you pay for all that machining you could have just bought a piston wit ha higher compression height.

The speedpro LF2315 is a good piston but it's HEAVY and it has no valve reliefs.

The best choice for a 383 is the Diamond piston , but it could stand to be a little taller CH than it is , the good thing is you can have that adjusted by them for not a lot of dough.


JohnRR, I'm curious. Would you recommend Diamond make them with a 1.932 CH? (I think they are 1.916 standard). The way I see it is that the block could be squared, and maybe not have to be decked a lot or at all, to bring the CR into a reasonable ratio with a closed chambered head. Please correct me if I'm wrong.


Square the block FIRST , once you know what the deck height is, and mock it up with the crank and rods you plan to use you can decide what CH you actually need and tell Diamond what you want. Their piston comes with a 5cc valve relief , the set I had done got a 3cc relief because I wanted a little something incase I changed my mind ... again ... and put in a cam that wasn't stock.

The good thing with Diamond is you can get a piston that isn't really available , I needed a .040 piston because of prior machine shop screw ups. I ended up with their 1.916 piston also because of 2 different shops screwing up when squaring the block. I'm probably the only person on the planet that has $5k into a STOCK build 383 short block ...

running up my post count some more .