I am trying to figure out what the engine is that I took out of our 89 IROC...it says GM 5.0 on back of block by head , one piece main engine , will load a pic of rf block but i fear that the bottom number is needed number and its somewhat illegible. not making sense of its origins using gm vin breakdowns

block stamping

 

 

The bottom # is the vehicle VIN that the block had been installed into. Last 6 digits are a sequential number, and the one before that is the assembly plant. Had it been a Camaro or Firebird, that digit there would have been "N" if it had been assembled in Norwood, or "L" if in Van Nuys. Being a 1-pc RMS block means it's 86-up, and since the Norwood plant was shut down around 87 (I happened to be in Cincinnati on business in late 85 when they announced that), it would most likely be "L" if it had come in one of our cars. Would certainly be "L" in a car from the 89 model year. The digit before that is the year; "A" was 80, "B" 81, and so on. If that "H" is that digit then the motor was originally in a model year 87.

"5.0" means it's a 305.

The top row is the "code" for what the block was. Probably still is whatever that was, since no one in their right mind ever "rebuilds" a 305. There are places you can look those up FWIW. Don't know too much about them myself though because I find that "information" COMPLETELY USELESS.

The ONLY REASON for wanting to know "where an engine came from" that makes ANY SENSE WHATSOEVER is to help decide what to do with it next. Since there are any number of ways to figure that out WITHOUT knowing "where it came from", and those other ways are VIRTUALLY ALWAYS more accurate than the "codes" (since if somebody has changed something about it, there's probably about a .000000001% chance they changed the "code" to match whatever they did, assuming even that what they did was consistent with any "code"), I'd recommend dropping the "code" line of inquiry which is likely to be either A DEAD END or just plain WRONG, neither of which is of much help to you.

Since it's a 305 and you've already replaced it, I'm going to assume it's headed to the scrap dealer. Are you needing to know something useful about it, like, how much it weighs, so you'll know what to expect when you haul it to the meltdown place? Doesn't too much matter what it came out of to make that guess.

 

Thanks , I really thought i had established that it was an 87 . yeah , basically scrap but ran nice , figured I may find some broke kid that needs an engine. Thanks!!!