best #'s on-line resource??

hey guys, where's the best on-line resource to check/verify casting numbers, serial numbers, etc? Engine, trans, etc.

I have an A833 4-speed I just picked up. would like to check the vintage etc. I was told it's from a 71 demon. it does have the 28 input / 30 output splines. 4.35 IBR.

i intend to make this work with my bb383... whatever it takes! currently looking for a 64 to 69 BB bell housing with the 4.35 IBR.

appreciate any help and, thanks!!