I don't think that would work?? 360 have larger radius on the pan and 273-340 is smaller... you could put a spacer on a 360 pan to use on other small blocks but not 360 with a spacer to use 273-340 pan
Other way around. 360 pan is smaller. Beyond me why Ma just had to change that. I believe someone actually did make a spacer. I actually cut a chunk out of two pans and welded one into another "back when" I put the 340 into the FJ-40 Landcruiser, converted a 360 truck pan into a 340 rear sump pan and a 340 car pan into a 360 car pan