As I mentioned in your other post, there is no such thing as a 261 babbit motor. There was a 235 babbit motor, not the same as the 235 post-'53. The 261 is a 235 with bigger cylinder castings that are bored to 3.75" and siamesed with each other. They are identical to the 235 except for the rods, head casting, thermostat housing, and oil passages (on late blocks). Most have captain's bars cast into the block above the starter and behind the exhaust manifolds. Late blocks have a head casting number ending in 850. I would make double sure this is a 261 before your purchase. Post the casting numbers here or visit inliners.org to find them.
