I bought a 70 z28 project this weekend. I know the engine isn't original, the only problem is what is it!!!! the casting # is 3970010; the #'s on the front passenger pad is: k10 06 CMJ. I think that makes it a '74 350. I cannot find the casting date code I pulled a valve cover and the casting # is: 333882. I hope someone can help me. Thanks, Rick

I think the motor you have is a 1970 350-350 - Check the numbers again it should be CNJ that was a 350 horse 4 speed car in 1970 did you check for a partial VIN by the oil filter ? I checked every book I have on engines -this is the only thing that I see that is close. Good Luck- what shape is the car in?

CMJ codes out to be either a 350 in '74 (police) or a 305 in '80 (full size/camaro). Check the block cast date for either year.

[This message has been edited by vfitom2aol.com (edited December 10, 2004).]

3970010 is a 4" bore block, so it can't be a 305. It would be the 74 model 350.

333882 is a common light duty head used on varoius Chevrolet vehicles (incl. 74-80 trucks) with 350 and 400 engine from 74-80

------------------
Mike

2002 Trans AM WS6 build #3124 - Pewter
2004 GMC E. Cab SLT Z71

I have the same engine and the CMJ code was used for several years in the mid 70's. Only way to tell is check the block date code and/or the vin number on the block under the alternator. For example mine is a 1975 350 L65 (145bhp) out of full size chevy assembled at St louis in 76. It's a 2 bolt main. You have to compare all the codes / dates to best determine what you've got.

First I want to take time to thank everyone that replied.

I am having a hard time locating the date code on the engine, but thats ok cause I am pretty sure its a 1974 350 motor. At some point its going to be pulled and either rebiult or replaced with something the Z28 deserves.

Is there another set of codes on the engine pad next to the engine number? Sometimes this code is on the rough block casting flange just up from oil filter, would be in a vertical position.

That would be the VIN derivative and would ID the Division, model year and final assembly plant from which the make and model can be narrowed down.

EXAMPLE of Vin Derivative
14L123456

------------------
Mike

2002 Trans AM WS6 build #3124 - Pewter
2004 GMC E. Cab SLT Z71