Inliners International Forums General Discussion Engines Trying to ID a Chevy 250

I have been trying to ID the engine that is currently in my 53 3100 pickup. It has the 3877178 block casting # with K 186 cast date, which I can decipher to a November 18, 1966 cast 230 or 250. The part that puzzles me is the stamp by the distributor which doesn't seem to follow the normal ID. This is F1123 FM. The only FM codes I can find are for 65 Impala 230, 65 Impala 250, or a 67 Camaro 250 The stamp is very distinct so the 3 is not an 8. Can anyone figure this out?

Thanks,
Charles

I don't have access to the distributor pad codes right now, but a Nov '66 casting could very well be in a early '67 Camaro

that casting was installed in Buick/Chevy/Olds/Pontiac 62-78
and can be either a 230 Or a 250 A more simple way to know what you have is Pull one of the Plugs and Look at the Piston If it is dished it's a 250 If it is a flat top it's a 230. The 230s& 250 shared the same Block and Head.

I am more puzzled about the date code stamped by the distributor tho. If the "F" stands for the month then that would be June and then the numbers make no sense. If the "F" stands for Flint Engine Plant the numbers still make no sense.

Charles

Hi Charles.
The first "F" stands for Flint, MI where the block was cast and built.
11= November
23= 23rd day
FM means it's a 230 from a '65 Biscayne/Bel Air/Impala/Caprice with a Power Glide.

OK that makes sense but doesn't seem to follow the info I have found about deciphering the codes. Also it can't be the 65 impala because it wasn't even cast, according to the casting date, of November 18, 1966(K186) so that leaves only the 67 Camaro as the most likely candidate.
Thanks to all for your help.

Charles

Is this "K 186" next to the cast letters "CON2"?

Yes it is. Right behind the dipstick tube.

Charles

I did some more checking and found that the code FM was used again in '66 to denote a 230/Powerglide combo. Still says it was in a Biscayne/Bel Air/Impala/Caprice. So my mistake.