Need help with motor numbers

[TXRookie]

I just pulled the motor out of my 68 C10 and I'm trying to figure out if its worth keeping or selling it, and buying a crate motor. I did some searching last night and figured out its a 350. But I can't figure out what the other numbers mean. I overheated the motor for the second time and it needs at a minimum a new headgasket. Not to mention I havent figured out why its overheating. Just trying to figure out what I have so I can get an idea of what its worth. ITs a complete motor from carb to to starter minus distributor. Anyway, I found the following numbers on the block.

3970010
V1207TM
04F368299

Any help would be appreciated.

[clay68c10]

The casting # 3970010 shows to be 302/327/350 2 or 4 bolt main. Probably a 327 or 350 since the 302 was the DZ302.
The TM part of your stamp code doesn't match that so maybe you are a letter off:
TM 1956 265 m/t 155 2 truck/3100
TM 1978 305 LG3 U 145 2 LeMans
I'd say pull a head and measure the bores, drop the pan and see what mains you have. If it's a 350 4 bolt, it would be worth keeping and rebuilding if you're looking to get a new eng anyway. Put in a new thermostat, radiator, hoses, and water pump and you're done. Really, those items are cheap and should be replaced if you just dropped the $ on a rebuild anyway.
I got the above info from MORTEC and Nastyz28.com.

[chev74]

i ahve heard that converting a 2 bolt main to a 4 bolt is actally stronger than a regular 4 bolt main. true?

[clay68c10]

I've heard that too, I think it's if you're using the aftermarket splayed-bolt billet caps.

[webfoot]

It is stronger but how radical are you gonna build it? I'd buy a forged rotating assembly before worrying about 4-bolt mains.