Not too much to worry about (once you know). all the bolt holes line up at the bellhousing end no problem as do the dowel pins so no worries there.
The engine mount lugs on the drivers side is approx. 5mm narrower than the standard 318. When you buy your 360 motor do try to get the engine mounts as well. This means that you can simply cut the 360 mount down to size, re-drill the mounting bolt holes using the 318 mount as a pattern.
Dont be tempted to use the 318 mount with spacers, that side of the engine can pull really hard under harsh acceleration and you dont want to lose the mounting lugs

There are support bars that (about 10"long) that run from midway along the engine block and mount to the gearbox bellhousing. The dirivers side is approx 1" too short. i used a strong stel spacer and a longer bolt which did the job fine. The later 360 had a bigger starter although my 318 fits fine and spins the motor OK too.
Yoo Will need a special flexplate if your going to use any other torque converter than one designed for the 360. I used TCI plate (approx ?90) which will fit the 11" convertor i have. These specialist plates remove the need to weld on weights on the convertor to allow external balance. B&M do a cheaper one butit only fit 9" and 10" convertors.