Just wondering if you guys would know if my original 396/402 thats in my 70 chevelle with build date of 69 would be externally balanced or internally balanced?

Only the 400 SB and the 454/502 BB's are externally balanced until they switched to the round crank flange and one piece crank seal on the SB's.

All the others are internally balanced.

pdq67

396 is internal.

good...Thanks for the help

All info above is correct and accurate.
But, just some added info. The SB400 and BB454 series engines CAN be internally balanced--------------------if you want to pay for it! These would be engines that a person had done at his machine shop, NOT factory internally balanced. Thus, a 400 or 454 which has been internally balanced will have a NEUTRAL harmonic balancer and neutral flywheel. And to the person who is not totally familiar with them, the internally balanced 400 may appear to be a 327-350 and the internally balanced 454 may appear to be a 396-427. It will be VERY, VERY rare that you run across an internally balanced SB400 or 454, but they are out there.