FTolliver

Hello, I need help!! I've Identifiied the engine as a 1968 350. The heads, I don't have a clue. On the front outside corner is casting # A2. On the front left bottom is a large 8. On the center, between the exhaust outlets, is #411 929. Rear outside is stamped 272.
Can anybody shed some light for me?

captjim

#8 heads are from a 73-76 350. Very large chamber that lowers compression ratio.

FTolliver

Thank you.

joe_padavano

I'm curious how you did that. The VIN derivative stamping on the driver's side of the block will tell you the year of manufacture.

FTolliver

OK, what I have is a 49 "88" coupe. It is a streetrod. When I bought the car, it was a 10 foot car. any closer you started to see the flaws. I'm now rebuilding the car. The party I purchsed the car from had made the remark, they put different heads on motor and couldn't get it to run. I made it run, but not to it's potential.
So bottom line I have a 68 block with "smog heads" and it can't breathe correctly?
When I get the car done, spring, I'll be more than happy to post pic's..

FTolliver

The block casting #395558 followed by a large 2

joe_padavano

All 350 motors from 1968 to 1976 used that same casting number. Again, you need to check the VIN derivative to know the build year.

FTolliver

OK. I'll check on that.
Thank you

FTolliver

OK, hope I did this right.
#66M159315, I got this off the surface between the head and block, front, left side.

69Rman

I believe that means it is a 1976 engine, at least it was originally in a 1976 vehicle.
I think your first 6 should really be a 3 though...

This number should take the form of "35Mxxxxxx" where:
3 = Oldsmobile division.
5 = year of manufacture (8=68, 9=69, 0=70, ..., 4=74, 5=75, 6=76, etc.).
M = location of manufacture (M = Lansing, B=Baltimore, X = Kansas City, Z = Fremont, CA, etc).
xxxxxx = last six digits of VIN of car that motor originally came in (original car's sequential production number).

Duane

svnt442

I concur. It looks to be a 76 block and heads. That's not entirely a bad thing as the block is a solid foundation to start with and the heads can be worked if you don't have the cash to find different ones.

FTolliver

COOL. I tried to take a picture of the number, didn't work even spraying white and wiping clean. Did make it more ledgable. With the #'s that came up, to compare,
66M159315 is what I read or the first two #'s could be 33M159315, or 36M159315. The first two #'s aren't that clear.

svnt442

Either way be it a 33 or 36 the 8 heads would have come on it.

captjim

Yep. 14cc dish piston with the large chamber yields a compression ratio of 7.8 to 1 +/- Not necessarily "smog heads" but ones with a large chamber. They need a little work, as do all the stock heads. Bolt on some early 350 heads and Cr bumps up to mid-high 8.xx to 1.