For some reason, I understand that the connecting rods are the biggest difference. I don't know why, but I understand that they have oil holes in them to lube the underside of the piston. I understand why, but I had a 22R Celica engine and the rods had those holes, so I don't know why they would exclude them from the N/A engine. I really don't know, but I heard that and if so that is a major difference. The other part about the different oil galleries I don't think are true. I know the block has a few plugs in the oil gallies and one is for feeding the turbo. There is a return plug in the oil pan already, at least on my 87 N/A. I also believe the pumps are the same but that is easily found out by asking to get the part numbers and see if each calls for a different number or not, I guess the same with the rods for that matter.
I can see rods being different but not a whole block, but Toyota does have a lot of money to spend on these things so maybe someone else knows for sure.
Russ
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