Please take a look at this picture:
http://www.classiccarauto.com/impala/how_to/find_tdc.shtml(page down a couple of pages and click on the photo for a larger view)
Looks like what I have on the front of my motor and supposedly came out of a 64 Chevrolet.
I'm not disagreeing with anyone, but when I found this pic, I thought my question was answered...
Thanks for the responses and any additional info. Casting numbers on the motor and heads and tag on the carb all point to normal 1964 283 car motor...but there are inconsistencies such as carb, water pump, valve covers, and Powerglide all bolted up with non-OEM bolts...but could simply have been pulled from original motor in a junkyard then other bits added back to make a complete motor.
May not matter much at this point as I'm looking at crate motors as a possible way to go, but I'm sort of curious at this point.