Thread: HELP with my Chevy 350 SB Engine Casting Number

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Can anybody tell me the details of my Engine? It reads on the block GM 12486570. I believe it is a Chevy 350 small block taken from a Corvette. I'm not sure what year the engine is. I'm not sure what year the Corvette it came out of is.

Please help!!!

http://www.minuit10.net/EngineCode/c...stingBlock.htm

HTTP://WWW.MORTEC.COM

Better than M goodwrench themselves :P

Originally posted by Bob Parmenter
http://www.minuit10.net/EngineCode/c...stingBlock.htm

Thanks, Bob, but it still didn't help me identify my casting number GM 12486570. It wasn't listed.

Originally posted by Quebec_Bastard
HTTP://WWW.MORTEC.COM

Better than M goodwrench themselves :P

Thanks, Mr. Bastard, but it still didn't help me identify my casting number GM 12486570. I guess Mortec doesn't have every fuc*** code. They didn't list that one. Thanks anyhow.

mc, perhaps what this means is you might want to double check your casting code?

That number doesn't match any I could find, you sure you've got it right? Drivers side of the block, just above where the transmission bolts up. They should be fairly large numbers. Be sure you clean all of the grease off because it can make one number look like another. If it's a 70's and early 80's vette, likely there is no difference between it and any other 350 of the time. The only engine you can tell if it is from a Corvette by the block casting number is the LT-5 which is also overhead cam, so it is obvious it is different. So, why even bother looking up the block casting number? Just put it in your car and if it goes good, it goes good. There is a pad on the front passenger side of the block just below where the head interfaces with the block, that will give you more information about where the block came from. Because of the 1 at the beggining of the number, this engine is most likely out of a late 80's GM car or truck or it is a goodwrench crate motor.

Streets, how did you find that number??? We know for fact it is a GM/Chevy motor. Three different people have read the GM12486570 clear as day, so we're sure it's the right number, located exactly where everyone says it is, driver's side on block toward back of engine up top. Crystal Clear.

Some conflicting stories I've read says it is the famous Chevy 350 small block engine. The 570 at the end represents the 5.70 litre engine or 350 cu. in. The next two from 570 towards left I've read could be the year. In my case, it's 86, so I would have a 1986 Chevy 350 small block engine. That's great if it is, but I'm not sure, these are speculative stories about serial numbers; I wanted other opinions per say.

What does the GM12486570 casting number tell me the type of engine I have? Any aces out there on defining casting numbers? I'm a little hesitant to imaguine it's a 361 Henway, but it could be???

Originally posted by mcdanida
I'm a little hesitant to imaguine it's a 361 Henway, but it could be???

You just made the geezer's day, he's loves to hook 'em!

If you're sure of the number, then it's probably a crate engine replacement block. Follow Street's advice and call GM directly, it's obvious several here have done a web search for you and that number doesn't turn up.

So tech are you telling that Henway 350 are craps cause already from the start they where mistakes?

OK, I got some phone numbers from GM on an e-mail I sent. I'll let everyone know my results. I do appreciate the responses I've received by all of you. This proves to be an awesome forum!

... and Streets, who knows, maybe the 350 small block isn't such a famous engine, but I was raised to think so. I had a 383 Hemi in a '69 Roadrunner I use to own, and I could take that sucker up to 150mph in no time. I took this Monte Carlo with this mystery engine to 140mph the other day and it didn't even float. It still wanted to GO!

The speedos on the 383 Hemi Road Runners where known to be off by at least 43 MPH. Comes out to 1 MPH per Cubic inch.

Weeg, are you saying I was traveling 193mph???

Wow, no wonder I had to change my shorts!