I think bellhousings from the V8 will fit all 250's. The trans is plenty strong enough but the site I found says they don't speed shift very well. They were designed to use behind the mid 60's chrysler V8's. If yours came from a Chevrolet Suburban/pickup if must be pretty strong...Rebuild kits are available by searching GM MY6 Transmission...
There also mention of some problems with wearing on one of the shafts. They felt the problem was because the oil used in these was ATF. They sggested a combo of regular trans oil and atf or 85-90 gear oil....Good Luck
