I have this old junker engine and I would like to run the codes before I go insane trying to dissassemble the rusted clunker. Has anyone done this before? I got the ones from the end of the block, where the flywheel is.

 

From that one I cant tell if it is a G or a C for the first letter. Hmmm. I dont know the signifigance of them; at first I glazed over them thinking well duh! Gm made the block. Then I tried to run this code on the other side:

 

Which one of these are signifigant? What do they mean?

Please reply, I need my sanity. If I tear it down and it is a 305 or something I will loose my sanity if it is not lost already Thanks in advance guys!!!

 

3956618....302.....69....4...Z-28 Camaro

from www.mortec.com

You just hit the jackpot buddy!!!

Don't touch that motor. Do not disturb ANYTHING WHATSOEVER about it. Put it in Hemmings Motor News, it is worth several times what it will take you to build a real nice 350.

 

according to "www.mortec.com" it could be one of three different motors, you will have to measure the stroke to find out which.

it's either a:

69---302 which is 4.00 bore x 3.00 stroke
68-69---327 which is 4.00 bore x 3.25 stroke
69 ---- 350 which is 4.00 bore x 3.48 stroke

as you can see the only difference is in the stroke of the crank, you could flip it over and pull the pan, then find the casting numbers on the crank, they should tell you which one it is.

of course, if the block is in good shape you can always get a aftermarket crank and build a nice 383 out of it.

 

I got excited and forgot to post a couple of things after all that....

Do pull the oil pan and see how many bolts are on the mains. I notice that it has a flex plate on it, which is impossible for a 69 Z28 302 in OE condition; so it might or might not still be a 302, or might have been one of the other 69 4.000" bore motors.

If it's a 302, in OE trim, it will have solid lifters; double-hump heads; and domed pistons. The crank will be steel. If all fo these conditions are met, it's the motor I referred to. If any of them are not, then either it's been altered, or it was one of the other motors.

 

I am like 99% sure that is is not a 69 302. Mainly because it had a 2 barrel Rochester and not the 2 Holley cross ram i believe that they came with. But the flex plate wouldnt rule it out because I knew that it at one point in it's tortured life was swapped into a powerglide Lemans. It is also a 2 bolt main. I am glad to hear that it is a 4 inch bore engine because it would be nice to have a 383 in any event. I have heard the 327 blocks are pretty rare, and people are willing to put up a couple grand for a numbers matching block on that end. The guy told me that it was a 400, never believed him but it is good to hear that I dont have nothing.

Even if it was a decent numbers matching motor, I dont think that it would be worth as much as it could because it is siezed solid, the intake bolts are really hammered.

O well guys! Thanks ALOT for the great and quick replies!

 

look in front of the passanger side head on the little ledge to the left of the water pump... what do the numbers there say? should have a partial vin from the origional vehicle it came from along with a date code and a suffix code all of which would be helpful in identifying what it is that you have.

 

It appears that the stamping is T0422HM if the pic isnt clear. This is on the deck surface of the passenger side head. There are some mubers to the side of that that are not really visible in the pic, and I'll have go after it with sandpaper to make them visible enough. I'll get back if those are needed, but I think these are the ones you are after.

 

Dope... forgot the pic.

 

T0422HM
Tonawanda, April22
1965 HM 327 a/c, trans ign, m/t 365 4 Vette/Chevy II
1968 HM 327 tur hydramatic 250 4 full size
1969 HM 350 a/t 250 2 full size/Chevy II
http://www.nastyz28.com/sbchevy/spcode5.html

 

If it was a 302:

- No flexplate (4 speeds only for Z/28, but easily changed)
- 4 bolt mains
- Forged crank
- Domed pistons
- Solid lifters
- Cast Aluminum valve covers with fins (originally anyway)
- Dual 4bbl aluminum intake OR hi-rise Single 4bbl
- Double Hump heads (#3927186) with accesory holes
- 2.02"/1.6" valves

 

Ya it would make alot of sense that it came with a '69 full size. In that case I hope it isnt to hammered like alot of those would be. Thanks guys! At least I know that it is worth tearing down and Magnafluxing.

 

and theres your answer.. it has 2 bolts mains 1969 HM 350 a/t 250 2 full size/Chevy II.. still a good block to start with IMO, good metal content and should be done with core shift by now.. might not be the gold mine a stock 302 woulda been but a good block to build up none the less.. what heads does it have on it?

 

O you reminded me... never checked that but always meant to.

Sweet! It has 441 castings... If they areny cracked they will be awesome heads to rebuild once upon a time. According to Lingenfelter, they are one of the better flowing per-"lightwieght" iron heads. I have some that I got off a local friend from this bored that are clean, decked, with new seals 88 Gta heads that I have massaged the combustion chambers but have yet to lay a valve job and pocket port on. I think those will be what will go on this engine, because after I machine the block I doubt that I will have the cash leftover to rebuild those heads. I am glad I have them though.

I am having a REAL hard time getting off the 4 bolts closest to the carb. They came rusted and stripped. What should I do... Drill them out?

And the distributor body seams to be "welded" to the intake manifold. I am still a noob on this tear down business but I didnt think it would be this hard.