I've got two slant six engine in my garage I am trying to identify.

1. #4R123339. Has tubes around plugs. The # was on a pad to the rear of the engine, just left of the oil pump.

2. #6225R 2 1 27. No tubes. The # was found above and to the right of the fuel pump.

Thanks for the help.

The engine number on the first engine will actually be found on a pad just below the frontmost spark plug on the block's deck surface. It's sandwiched between the head and the coil/alternator support bracket and probably needs scraping and cleaning so you can read it.

I am fairly certain your 2nd engine is a 1976 225 with a cast crankshaft, but not entirely certain.

SlantSixDan: Thanks. I guess a combination of bifolcals and poor lighthad me stumped. Found the number after a little "cleaning": 3W 225 4443.

Sounds like maybe a '63 motor?

Nope, a '63 engine would say "T22" (for an iron 225), "T17" (for a 170) or "TA22" (for an aluminum 225). The use of the full engine displacement didn't start until about '69 or '70, prior to which only the first two digits were used on the ID plate (17 for 170, 22 for a 225, 31 for a 318...). I think your "with plug tubes" engine is probably a '73. Five freeze plugs in a straight line over on the manifold side of the block, right?

SlantSixDan: Absolutely correct - 5 plugs.

They had only 3 plugs, in a shallow triangular pattern, until about '67. So I think '73 is probably correct.

3W 225 4443

3 - 1973 model year
W - Windsor engine plant
225- 225-cid
4443 - build date - September 26, 1973 (would check this number)

_________________
Bill
Vancouver, BC

The "4R123339" is part of the VIN of the vehicle the engine was installed.

4 - 1974 model year
R - Windsor, Ontario assembly plant
123339 - 23,339th 1974 vehicle built

The engine number will be located on a machined pad just below the #1 cylinder along the top edge of the block.


6 225 R 2 1 27
6 - 1976 model year
225 - 225-cid
R - Regular fuel
2 - Assembled in February ...
1 - on the 1st day
27 - 27th engine built that day

Check for a number stamped on the rear of the engine.

_________________
Bill
Vancouver, BC

Thanks to all who responded. I sold the '73 motor and didn't feel comfortable selling it without giving the new owner as much info about it as possible.