318 v 360

If you can do the work yourself that'll save a bunch. I did mine for about $1600 but I already had the 360 block and some 340 X heads. If you shop the parts for sale section here and on Moparts and a few other boards you might find a good deal on an already built 360. Just check out the buyer to make sure it's done right.

Also don't forget the engine is only one part of the package. With the 360 in mine I run a 3000 stall and 3.55 gears. When you use a cam big enough to make 375-400 hp you definitely need a loose converter or it'll be a temperamental pig. You'll also need decent gears or it'll be a dog on take off. Another thing is to use a 360 you need to either use a properly weighted 360 converter or use a B&M flexplate balanced for a 360.