Posted by Don W. on October 20, 1999 at 19:43:57:
In Reply to: Re: 78 powerwagon engine swap posted by dc on October 20, 1999 at 07:03:18:
I have a '73 that was originally a 318 and I put in a 360. It's not a 440 but it is a major improvement. There are four areas to be aware of when going from 318 to 360.
(1) Most important! Most if not all 318's are internally balanced. I don't know for sure about anything newer than 73. All 360's are externally balanced. What this means is that you must use a 360 harmonic balancer. You must also use a 360 flywheel or flexplate depending on whether you have a manual or automatic transmission. The 318 stuff will bolt on but you will end up with serious vibration problems.
(2) The 360 uses a different oil pan from the 318. Again, the 318 stuff will bolt on but there will be a gap at the rear main. Just use a 360 truck oil pan. The 318 oil pickup is fine.
(3) If you have a manual transmission and the 360 had an automatic on it you will need a special crankshaft pilot bushing. The pilot bushing hole in the automatic crankshafts is smaller in diameter than on the straight drive crankshafts. I had to buy the 360 pilot bushing and have it turned down to fit the smaller hole. Not a big deal.
(4) The 360 uses a slightly different motor mount from the 318. I think it is the one on the passenger side but it has been too long ago for me to say for sure. (I do much better documentation now than I used to.) Just check the factory parts books to find out for sure on this one. BTW, I'm talking about the U-shaped steel piece, not the rubber isolator.
All in all this is an easy swap and well worth the effort. As far as the 440 goes, If this is your first swap I would go with the 360. After that you'll be ready for the 440. Good luck.