77 motorhome 440 vs 71 360-what to use???

OK - IMO, I am assuming you are keeping the short block from both and that IS the starting point. The MH 440 should be steel crank low compression (assumption). On the cheap, you will need a new oil pan set up, heads, intake, cam and ignition. Not a fan of Procomp, but they have the small chamber heads which will increase your compression, MP cam @ about 474 and Craigslist intake with a Napa electronic distributor and MP box from Summit oh and factory PR. Rockers and shafts you can use from the MH, valve covers etc and you will be close to the 400 range. The MH transmission may be an issue, if it has the large brake on the rear, you will need to swap that or get a whole new one. And water pump

As for the 360, not sure what base you are starting at, so you will now better.