help me ID this

[chevytruckfan]

OK just got my truck home yesterday and started going through it making sure it is safe to drive. As I was checking everthing I also wrote down all the ID numbers on the engine block I have 44 GM 3970010 what type and year is this engine, and anyway to tell what vehicle it came out of? I looked on both front and back of the heads I could not find the #. Anyone know where to look? Same for the trans but I do know it is a TH350 by the shape of the pan and location of the module. I pulled the rear diff cover off and on the ring gear I have 3817778 11:41 GM 12-71. It is a 12 bolt and with the ratio stamped on it, it is a 3:73 rear, but not sure if it is posi? I did not see any springs in the carrier unit just Ring, pinion, and spider gears. But with one wheel off the ground I would not turn. With both wheels off the ground the opposite would spin in the counter direction?

[krue]

If your rear end looks like this it's a plain old open differential.

[krue]

From Mortec.com (a good site for running numbers).
3970010....302.....69....4...Z-28 Camaro
3970010....327.....69....2...Trucks and industrial
3970010....350...69-80...2 or 4
BTW you have to pull the valve covers to get the head numbers. You can look them up on Mortec also.

[Stocker]

Originally Posted by chevytruckfan

not sure if it is posi? With both wheels off the ground the opposite would spin in the counter direction?

Opposite wheel spins in opposite direction = open diff, no posi.

[chevytruckfan]

Yep that pic looks like mine no posi. Oh well. I did get a 12 bolt with decent gear ratio. Thanks for the info.