gm 8" Balancer CAST 3860010

[67rs/ss]

What was this gm balancer used for? The number cast into the balancer is 3860010.
I know that 3860010 is also the part # on the box for a cast #'d 3870325 balancer.

[Jonesy]

Looks like a 69 396/375hp 8 inch balancer. Corvette, Camaro, Chevelle, Nova

[67rs/ss]

Thanks for the reply. I also would like to know how to decode the date code if this is what
it is. The cast:
3860010 has F G 5
3870325 has G 7 F and and another one with E 7 F
I have several of these I got a few years ago when I bought out some parts
from a retired drag racer.