casting numbers...

[yourownself]

so, i have a 2 bolt 350 mystery block that was given to me a little over a year ago, and just got into tearing into it tonight.

on the heads and crank, i found the casting number "3982441", but could find nothing that resembles a casting number on the block.

i DO know it's been bored .010 over, or at least been aggressively honed at one point, two of the cylinders are scored, and it smokes REAL bad.

oh yah, the valves are 1.50/1.94.

now, the casting number in the heads and crank are perfectly clear, so i KNOW i'm not reading it wrong.

i cannot find any information on this casting number ANYWHERE!!!

does anyone have any obscure manuals or anything with a more complete list as i have been able to find online?

i was told it could possibly be from a 69 camaro, but that could be a random guess.

pistons are flat with valve relieves and appear to be original gm pistons, only installed in the wrong order (some are numbered, but seem to be out of order)

the motor allegedly put out some good power, despite an obvious compression loss on two cyl's


anyone have any idea as to where this damn thing could have come from?

again, the casting number is 3982441.

thanks, fellas!

 

[85 Cutlass Brougham]

The casting number should be on the back of the block between the back of the intake manifold and the bellhousing mounting flange. It's right on top and should be easy enough to read. Also, there is a pad that is part of the block deck that is in front of the head on the passenger's side of the block. If it has never been decked, this stamping should still be legible and will give you a 3 character code that will let you know what it is from. For example, a CTB code is a 1970 LT-1 Z-28 block IIRC. I think I posted a link on here somewhere from when I was trying to decode my block, if you want to do a search.

Also, if it is from a 1969 Camaro originally, it will have a standpipe on the intake manifold for the oil fill and breather, and I believe the heads will not have the ends drilled for the accessory bracket mounts. I think GM switched their mounting holes in 1970 or so.

 

[yourownself]

there's no intake, just a long block, but i'll take a look at the heads to see about those mounting holes

 

[85 Cutlass Brougham]

Well, it's not on the intake! It's part of the block behind the intake and is usually obscured by the distributor. I can read mine in the car, but it is right up close to the firewall.

 

[midwestls]

this should help you... http://www.mortec.com/castnum.htm

 

[yourownself]

anyone have a good list of crank and head casting numbers now, so i can figure out if i have a 350 or 327?

one of the lists i came across said the block was a 302, which i doubt, unless a 302 had a 4.00" bore!

 

[85 Cutlass Brougham]

Well... a 302 DOES have a 4 inch bore. If it is an original 302 block, it's worth quite a bit of money. They were only installed in 26,815 cars as it was a Z-28 specific engine used only from 1967-69 (602 67's, 7,199 68's and 19,014 1969's). If it is a 302 it should have 4 bolt mains, and a forged 3 inch stroke crank. There are several stamping codes for 302's, but the best known is "DZ".

Now if it's a 327, it will have a 4 in bore and a 3.25in stroke, and a 350 is 4.00x3.48. If you have the heads off, it's easy to determine what it is with a ruler. Just put a piston at BDC and see how far down the hole it is.

 

[midwestls]

if you go down lower on that link I gave you it also lists head casting #'s 😀

 

[yourownself]

haaaaaaaaa, i was gettin' pissed because nobody had 3982441 listed as a head number, and i decided to check out the other head, and take another look at the crank. turns out that 8 was a 3.
3932441. 69 passenger car, 76 cc heads, 3.84 stroke.

a plain 'ol 350. now the reconstruction can begin