Engine decoding. What a pain...

[COBALT]

Last night I made my third attempt at finding codes on my engine (350-not original).

I found the casting number on back part of the driver's side behind the head (3970010, or something like that), which tells me it's a 2 or 4 bolt main 350 between '69 and '80. Yippie. I already knew that.

...but I haven't been able to find much else, and climbing around on top of the motor is getting old quick. I checked all along the block where the heads attach to see if anything is stamped in the block, but there's nothing there. I also looked behind the passenger side head and found a couple of casting symbols (an "S" I think), plus what may be a three number code but that's about it.

My goal here is to find out WHERE this engine came from. The more I work on it the bigger the mystery. Can anyone clue me in as to where information would be to help me solve this puzzle?

[Burlinator]

on hte block on passenger side in the front of the head but if it has ever been decked it might be gone

[COBALT]

That'll put it right behind my alternator (not original accessories either). That means I'll have to pull the alternator just to get a peak.

Lovely. Anyone else have any ideas?

[Fast68Chevy]

no you dont.,,,,,,

all you need is a flashlight a rag and a long flat screwdriver, first scrape off the pad flat surface real clean with driver then stick rag on end of it and wipe it off and then use flashlight to get the last three letters of the code, the larger digits not the little ones under that

stick thwe driver up under the alt from the pass side to get to the pad

if the code begins with a T then it should be a 4 bolt, if you have 350 listed on glovebox door then chances are its original engine, but alternator and stuff is not original set up from sounds of it,
so maybe engine has been swapped after all

easycake

[COBALT]

I'm going to need patience. I'll try again tonight...

[lux hauler]

Look where the white arrow is....under the head. That is where you will find the numbers.

[COBALT]

I found them! Here they are.

V0327TDR - thin big letters outlined in blue (nearest to block)

C8Z172910 - smaller deeper letters (below the first set)

My code books say "TDR" is either a 1972 K10 & 20, or 1980 C-10 & 1500 series truck. Can anyone confirm/deny this?

What about the other numbers?

[bobs409]

Mad Mikes suffix code chart agrees with that. Either a 1972 or 1980 350. Definetly a truck engine. Whenever there is a "T", it's a truck engine.

The other group of numbers should be build plant, year and part of the VIN from the original vehicle. Im not up on these so someone else might be able to help there.

[Blazer1970]

I'm gonna say that it is the 1980 engine since they did not put VIN numbers on truck engines in 1972.