See the code marked on the piston, says 3683 and T333

After tearing my engine apart to freshen up for a boost build I noticed that the block had some pistons I’ve never seen before, slightly dished with a dot on top facing the front of the block. I’ve seen similar ones with a “plus” symbol in the center, same dip but not any with out one.


I also noticed that my rods were dirtier than the bottom of the pistons which makes me think that the pistons were once changed out before?? I got out a tape measure and measured my bore and got 4” doesn't look bored out. I know I’ll need a caliper to get a more accurate reading.

Any way, just wanted to see if anyone can tell me if these are in fact stock lq9 pistons. I’ve tried to look online for ls stock piston pictures but all I get is companies showing their aftermarket pistons.

Look like stock Lq4 to me. lq9 should have flat tops

Dang! The guy I bought it from told me it was an lq9. Oh well I guess im Better off with an lq4 for boost.

Thanks for the quick info guys!