Readying to drop a 440 in one of my 71's. Do I need a front or rear sump pan? Is axle clearance an issue with the correct big block pan if I lower the truck? The 318 in my other 71 rubs the back of the sump on the axle on sizeable bumps with the 70's 4wd front flat springs (was good for 3-4 inch drop, but waaay too stiff). Also, most of my pieces in inventory are motor home parts. Have exhaust manifolds 4041468 and 3769103. Any problem fitting these? the passenger sides a center dump, but the driver is more forward. Seems this should work, but wont know until I try unless someone has words of wisdom. Any advice and help is appreciated!