The Stovebolt Site Forums The Shop Area Engine Shop 350 to ad manual box?

I understand some of the parts other guys use might be hard to come by in the UK, but some of the other approaches require no automotive parts, just work and a little steel.

Unless someone has already changed the rear axle under your truck you are very limited in both your gear ratio choices and your transmission choices because of the closed or torque tube type rear axle.

Modernizing the running gear under your truck probably starts with choosing a new rear axle. I have no idea what's in junk yards in the UK so I can't advise you there. You need to change rears to convert from closed to open driveline. Until you've done that you are stuck using only the couple of transmissions made for a closed drive system.

There is an exception in that a kit is made that adapts a Saginaw 4-speed to the torque tube. If you do that you need the same bell housing we've already mentioned and unless you change the ratio in the rear you have the same limitations on speed.

The kit is sold by Patrick's Antiques or something close to that. I've heard only good reports, but have not dealt with him myself. And you'd be ordering parts from the US to do this.

Otherwise any modern automatic transmission and any over drive manual is going to require changing the rear axle.

I guess one UK junk yard possibility exists that I forgot about. I've seen pictures of Jaguar IFS and IRS under one of these trucks. I'm told XJ- stuff isn't as hard to come by around there as it is here, and here its pretty cheap and easy to find.

Of course that does nothing about your transmission problem, but since you really need to resolve the rear gears issue first its a step in the right direction.