All small blocks share same crank ?

Thanks guys. I’ve been chasing a driveline vibration at 70mph. Addressed many things to no avail. Only thing I haven’t addressed yet. Is driveshaft balance and tranny mount. Which I ll do both soon. If that’s not it. The crank may be bent or out of balance. That’s the only other option left I see. But, nothing vibrates when car is in motion under 70. Does anyone sell a 360 crank new for a 72 engine ?