I have 64 Valiant. 170, cracked waterjacket. I have a 70s Aspen 225 from a salvage yard. The engine is stamped 72 25R 1 252 E below the head. What do these numbers mean? I hope to put an older plug tube style head on it. Is there a problem with this?

No problem with swapping the head (all slant six heads are intechangeable) but you may have difficulty swapping the engie in if you have a transmission. In 68 the hole in the center of the hub chenged size and I know that you either can't mate a late engine to early transmission or a late transmission to early engine (I forget which one). If you have a manual transmission you don't have to worry about this.

There's no problem swapping a '68 or newer engine onto a '67 or earlier transmission, either automatic or manual. All you have to do, if you have an automatic, is get the 1/8" annular adaptor ring from Pat Blais. if you leave this out, you'll destroy front pump bearings and seals early and often.

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Too many people who were born on third base actually believe they've hit a triple.

What about the numbers? I want to get the correct parts for a possible rebuild. Is there an easy way to find out if it has been rebuilt previously? I have not opened up the botton end yet. It may not even need a rebuild
Seeing the cost of kits. That would be nice