I have to send a pair of upgraded 72c's out of state to be installed in a 40 scarab this winter, there is a possibility they will be replacing 71's. If this is the case, should I expect to need to move the engines forward to accommodate the extra length of the 72's? They will be trs tail stocks.

yes i think about 1inch,if you have solid mounts you can make a thick spacer

Yes it is 1"

Thanks, I'll pass it along