"air intake coming over the top or something...." That would be pre "77" but how "pre" I dont know.
I bought an engine off eBay.....when I got it home and started looking at it real good, I discovered it was a auto tranny block (12 not 10 in the eng # ), the PO had installed the clutch, there is "82" stamped on the rod bearings, the head has 12mm GPs, so maybe "82" with the block. The power steering pump, air intake, motor mounts were all the pre "77". I dont know how long that basic engine was built but you could "mix and match" for a long time.
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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug
"Lifes too short to drive a boring car"