Help To Id Motor

[Chevymaniac]

Hey everyone, i need help identify this big block i got from my friend. It's a 396 chevy BBC. It was pulled from a 71 GMC 3/4 ton 4x4. Motor was not orginal to truck. My friend told me the motor came from a 68/69 chevelle. When i pulled the numbers off the motor i'am getting conflicting info. Would like to know exact specs of motor and where it orginally came from. All help would be much appreciated.


Casting numbers# 3955272 Found on the back of block, drivers side
3872702 Found on cylinder head
T0502JQ Found on front of block, passenger side
192096826 Found on front of block, passenger side
3883948 Found on top of intake, behind carb area
T, CONV1, GM5, PASS, B14 9 Found on the back of motor
where the bellhousing bolts to the block
GM1, T Found on intake

Thanks for any light shed on subject.