There are 3 or 4 more big bolts on the sides and top of the transmission..If you can not unbolt the converter from the flex plate, (after you get the dust cover off, clean it up and get under there with some decent LIGHT) then the engine will have to be moved forward a considerable distance, 5 or 6 inches, to allow the transmission input shaft to clear the converter. Be sure to support the transmission while the engine is being pulled..
Your 360 cu.in. engine is externally balanced, there will be a big lump of steel welded to the converter..Should you replace the engine with a 318 cu.in. motor, be sure to remove that balance weight as 318's (5.2L) are internally balanced and do not need it.. It's always easier to have the converter in place on the transmission when installing the replacement engine..