Engine origin

[Dcm]

I have a 1970 swb half ton fleet side with cool spring rear suspension. The info from decoding the vin says the truck came from St. Louis and had a V8 and a 4 speed manual tranny. The engine "looks" original (ram horn exhaust manifold, chevy intake and heads, quadrajet carb). But when I ran the numbers on the engine it came up with an age range bracket of 74-78. The numbers on the intake point to a car from mid 70's with a four barrel. The vin on engine doesn't match vin on truck. Is this a fairly common occurance and are there any "gotcha's" to watch out for?

[wreckedchevy]

I'm guessing they probably swapped motors at some point I know in the 21 years I've owned mine I've rebuilt the original 250-6 then installed: 350, 307, and currently running a 305 out of a mid 80's c10

[zeldman]

I would say that in the last 44 years someone has swapped out the 307 for a 350, and put a 4 BBL carb on it. Not unusual at all.

[davepl]

If there's a VIN on your engine, it's not for one of these trucks. Sadly we got casting code (the 3-letter code) and not much more. There is no partial VIN or even sequence number on truck engines.

So just the fact it has a vin excludes it, and the dates back that up.

If not being the original engine is OK with you, just make sure it's not a 305 instead of a 350. I seem to recall it not being that easy to distinguish for some reason.

[Dcm]

As long as the engine is a usable 350 block, I'm happy. And according to the casting info, it's a 350. 3970014CMA

[Hutch]

Decodes as
CMA 1974 350 Turbo Hydro trans. - - 2 Barrel carb Body A B F X

information from http://www.nastyz28.com/gm-chevy-cod...s-suffix-2.php