360 Internal or External Balance??

It wouldn't hurt if you have the time and space. It's just a matter of finding a customer. But there are a few people who occasionally look for whole 273's for other parts or to race in class.

But as mentioned before, very early 273's had a small converter snout register which will not accept the common, later converters, unless someone machines it out. I just don't remember the transition years. But either way, anytime you start swapping parts around - 273, 318 or 340, the rotating assembly needs to be checked for proper balance.