@metal shaper; ANY sbc bell housing from '55/2 - '86 will fit the 250. Any sbc '55/2 - '72 bell should bolt to the 250 AND to your rear mount crossmember IF (big if) you have the sloping mount saddles instead of the flat ones. 1969 - 1972 have the large line up cutout or hole for the front bearing carrier on the tranny.
Les
