Slant 6 engine stamping help.

Im trying to replace the 225 in my '68 Valiant. I am aware of the crankshaft pilot hole differences and I am trying to figure out which one mine is while its still in the car. The casting numbers on the block are 2463430-16. The boss is stamped 225 1029. One date code decoder puts this at May '64 but this is unlikely because my car has 108k on it and it looks like a bolt has never been turned on it. Could someone please tell me how to identify if I have the early or late style so I can select a replacement engine based on this?

The block number is more like that of an mid-early block. Does it have 3 core plugs in the driver's side of the block or 5? Of course if it has been rebuilt, then all bets are off to decipher the crank pilot sizing by the block numbers.

One problem that has confused me is that service part numbers (i.e., replacement part numbers covering several years and parts variations) have been publised as production numbers. So many PN's you find published are not accurate as to production PN's.

qwksi1 said:

Im trying to replace the 225 in my '68 Valiant. I am aware of the crankshaft pilot hole differences and I am trying to figure out which one mine is while its still in the car. The casting numbers on the block are 2463430-16. The boss is stamped 225 1029. One date code decoder puts this at May '64 but this is unlikely because my car has 108k on it and it looks like a bolt has never been turned on it. Could someone please tell me how to identify if I have the early or late style so I can select a replacement engine based on this?

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This engine block of mine is from about 1966...has 3 welsh plugs.............and your saying your car is a 68 model.....I'd say the donk has been replaced once upon a time.

Yes, mine looks like that and appears to have 3 plugs. I thought that it was unlikely that it was changed, all the hardware was original. I just replaced the original PCV valve last week. It lost the rear main seal and the oil light wasn't hooked up from the previous owner painting it. I ran it a long way with no oil, it blew up but still runs. I was hoping to find an engine first so I could keep it together to move in and out of the garage until I'm ready to change it. Guess Ill probably have to abandon that at just pull the trans and find out.

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