Internal or External Balancing - sbc 350 (3970014

[malticefalcon]

Ok, I decided a while ago that I was going to build an engine. I have dropped them in and worked on them but have never built one from scratch. So I bought a sbc 350 that I want to drop in my 69 camaro. Thought I would by a few parts and that would be it. Wrong...... I have had to research cams, timing covers, fuel pumps, oil pumps, bolts and on and on. I am JEGS #1 customer right now. So I have my list of parts almost complet and I am assembling the engine and I get to installing the timing cover. But I can't buy a timing pointer because I need a harmonic balancer. S oI call JEGS and ask what they recommend and the first question is, "is the engine internally or externally balanced." No clue. So the guy tells me to check the GM number on the block behind the driver head and it reads 3970014 and he tells me to call GM.

I figure I can get a quick answer from here. What do you guys think. My engine block is a 3970014 and is a 2 bolt main. Looks like it came off a 70-76 camaro. I need to buy a balancer but need to know if it is internaaly or externally balanced.

Waht do you think?