transmission/rear end combo

With a 318, I would go with an 8 1/4 rear. You can have a whole rear ready to bolt in for less than the cost of a good 8 3/4 pumpkin. It will handle all the 318 will throw at it. Rear disk brakes from a Cherokee will also work on the 8 1/4, and you can find all kinds of gear ratios for them too.

8 3/4 rears are fantastic but one is not needed in this application. My 8 1/4 handled 300,000 miles of slant six cruising/towing, and lots of burnouts from my 318, and some flogging from my 340 too. Doesn't make a bit of noise and is still going strong. They're good rears. :glasses7:

The 904 is a good transmission but I'm not very familiar with them. I'm sure someone will chime in with more info on them.