thejman92

Hey guys, I need a little help.

My 87's 305 just bit the dust and I needed a new engine. Found one that's rebuilt and looks in excellent condition. But I'm trying to get some info off the numbers from the block with not much luck.

Here's what I got and if any of you can dig up some info on it (year, HP rating, previous application, etc...) That would be great!

Front passenger side tab:
141601965 K08 24 CMR
Rear end of block drivers side:
GM 3970010
Rear-upper mid block above flywheel:
K 12

Thanks!

Westech

I just googled 3970010 Gm block.... came up with LOTS of info.

1969 350 4 bolt.

thejman92

Thanks Westech,

I did the same for most the number I but keep getting mixed info. Especially for the 141601965 number. I can't find that anywhere. Also, it's definitely a 2 bolt. I saw that for sure when I looked at the block.

Night rider327

iTrader: (13)

So it looks like that's a 1974 350, 145 HP A body engine
8.5:1 compression
145 HP @ 3600 rpm
250 ft lbs torque @ 2200 rpm

Being you said it's been rebuilt non of this is really valid.. It could be a 100 HP or 400 HP, could even be a 302, 327, 350, 383, etc depending on crank used.


Here is the break down on your codes...

K0824 Is the prefix code, CMR is the suffix code
K = St. Catherines, Ontario
(McKinnon Industries Canada)
08 = Aug.
24 = 24th day
CMR = Has 3 listings

CMR...1974...350...tur hydro trans...145 HP...2bbl carb...Used in A body cars
CMR...1978...350...man. trans...L82 RPO code...220 HP...4bbl carb...Used in Vette/Z-28
CMR...1980...305...auto trans...H VIN code... LG4 RPO code...155 HP...4bbl carb...Used in full size cars

141601965 is the VIN sequence of car engine was installed in (not the VIN of car though)
1= Chevy
4= Last digit of year 19x4 (1974 in this case)
1= Oshawa #2 plant Canada
601965 = Production sequence of vehicle VIN

3970010 Is block casting number and probably chevy's most used number. It's a 4" bore block, 2 or 4 bolt main from 1968 to 1980.. Could be 302, 327, or 350

AlkyIROC

Glad someone beat me to putting up all that info.

So the original engine was a 1974 350. Since the one you found has been "rebuilt" all the rest of the information means nothing. Different pistons, different camshaft etc means it's not original any more.

You simply need to look at it as a rebuilt mid 70's 350 with an 010 block. Providing it's been rebuilt properly and not just slapped together, it's still a desirable engine. Still a lot better than a 305.

mhatfield 14

Where is the best place to get this information?

sofakingdom

iTrader: (1)

Head casting number, piston part number, measurements of ALL machine work that has (or hasn't) been done to the block, crankshaft and heads, and cam part #.

The numbers on the block are UTTERLY WORTHLESS, except for the casting number, for telling you ANYTHING AT ALL about THE ENGINE. They only tell about THE BLOCK. They tell NOTHING WHATSOEVER about all those other things I mentioned that a "rebuilder" (professional or otherwise) changes EVERY SINGLE TIME. Virtually NO motor EVER gets put back together exactly like it came from the factory in ANY, let alone ALL, of those other critical details, meaning that whatever you have now, is ALTOGETHER DIFFERENT IN EVERY WAY from whatever those number on THE BLOCK are related to.

About the only thing that's likely to be "the same" as the sedan 350 2-bbl that it started out as, is the heads; common "rebuilder" behavior is to stick the most common, dreadful, ordinary, undesirable head castings on such a motor, because that's what they've got the most of laying around. Expect 882 or 624 to have been used, which are the ones off of those lowest-of-the-low-performance mules from the mid 70s. Similarly, expect a copy of the 929 cam, also used in those motors; .390"/.410" lift, approx. 194/204 duration @ .050". As far as pistons, rebuilders almost always build very low compression motors, since higher compression ones tend to cause problems when installed in unfavorable settings by inexperienced hacks trying to spend the fewest pennies possible, and thus cause more "comebacks" than low compression ones. Expect dished pistons with the extra .020" or "rebuilder" deck clearance (they almost all have that), which will put the compression just shy of 8:1. They typically do the bare minimum of machine work, which would include only boring, honing, and cleanup; no attempts are usually made to improve on the block in any way.

Only way to know what it is, is to inspect and measure EVERY SINGLE part. Beyond that, put it in a car and see what it does.

It's impossible to tell you what you're looking at for sure given the info you have thus far; but if it's REEEEEEEL CHEEEEEEEEEEEEP, then it's probably about like what I described above. Best thing you can do is talk to whoever rebuilt it and get more details. However if you can tell us more about the setting in which it is being offered for sale and the price, we might be able to make a fairly accurate guess as to what it is, as many such things are highly standardized across the industry.

Night rider327

iTrader: (13)

http://www.nastyz28.com/sbchevy/sblock.html
http://www.nastyz28.com/chevy-engine-code-stampings.php
http://www.nastyz28.com/sbchevy/sblock.html#general

http://www.73-87.com/chevy_ids/sbcid2.htm

http://www.1968ss.com/sbcsuffix.asp
http://www.1968ss.com/SBheadnumbers.asp
http://www.1968ss.com/SBcranknumbers.asp

http://www.mortec.com/

And of course the SA-1 books/manuals not free but more info/listing and more of the late model stuff.

It's hard to find suffix codes online free for like the 96-00 vortec engines but the SA-1 book has them listed