I'm re-ringing a low mileage rebuilt 2.3 to have ready when the original gives up the ghost. In tearing it down and inspecting it, I've found a few contradictions . The block was bores 1mm over and the crank turned .5mm on the rods and mains. Where things got strange are looking at the crank and rear main seal. The crank has apparently had the slinger machined off, and the seal is a one piece..... but not a press in like 302. It looks like the 2 piece, but not split and goes around the crank flange before you set the crank back in the block. You bolt the rear main cap down and it compresses it in the block sealing it. Cool design, but I've never seen another like it (sorry, no pic of it). Is this an aftermarket design or from a later/obscure 2.3?