If it's a large journal 327, it's a 350 block anyway. Only difference between a 327 and 350, and I do mean the ONLY differences is the crank, and the compression height on the pistons. Past that, identical motors. Same Con rods, push rods, heads, balancer and all. So if it's a 68-69 327 it's a 350 block. Run with it. It'll be a good running motor. Then when you rebuild it later on down the road, simply buy a 350 engine kit and find you a very easily commonly found 350 crank and put it together, now it's a 350.
If it's a 62-67 327, then it's the small journal 327 with a forged crank. Those motors love rpm and run forever and ever and ever and huhhhhhhhhhhhh ever and ever and ever. But, a 350 crank won't fit the small journal motor and the con rods do NOT interchange with the 350.
At any rate, either one of the 327's are good motors. So if it's a good running motor and runs good now, grab it and go with it. Nothing wrong with a good 327. 350 has a bit more torque and that's about the only difference. And being realistic, if it's a pre 69 motor, chances are it has more compression, hp/torque than say a 76-86 350 due to smogger heads and decammed motors for gubment emmisions. Rock with it is my suggestion.
