The Stovebolt Site Forums The Shop Area Driveline diff change

recently purchased a 48 CHEV 3/4 factory flatbed truck. I have the opportunity to purchase a 1989 light duty 3/4 ton chev. thinking I might like to put the complete diff under the 48, and try to adapt the frt disc brake system along with the dual master cylinder. any thought,s suggestion,s or advise ? THANK,S DOUG

Hy z48, there are a couple of ongoing discussions here on the subject of disc brake conversion of the front axle, one in the "Big Bolts" forum, and one in the "Tons o fun" forum. As to the rear axle, you will probably have to relocate the spring pads, but should be a fairly easy swap, I imagine the track is wider on the new rear axle, so as long as that is not a concern go ahead with it. Don't forget about your pinion angle. Have you seen the B.C. Bolters forum further down the page, there are quite a few of us on here.

I bet that axle is going to be somewhat too wide, even for a flatbed. Measure the track widths to see how different it is.

My dad bought an '88 light 3/4-ton 4x4 brand new, then passed it on to me several years ago. I've since sold it - the vehicle was always something of a lemon, blowing up a couple of transmissions and transfer cases, along with numerous sections of the electrical system, within less than 100k miles of mostly garaged and very well-maintained service. My personal opinion would be to find a better starting point for conversion parts.

When you say "light duty," what do you mean? Is it a 3/4 ton with the semi float 8 lug rearend or the 6 lug rearend? If I recall, they had both back then.

white dog, it is a semi-float 8 lug. havent measured the width yet. I have available a 74 full float diff. this one is a 14 bolt, would this be a better choice ? thank,s Doug

The semi-float would be alright. They are plenty strong and lots of parts and available gear options. If I remember right, the semi float is a little narrower than the full float 3/4 ton version. The full float would be a good choice too, since you have a flatbed and no fenders to worry about. If you wanted to narrow things up a bit, you could find some dually hubs and install them on the full floater. Of course, you'd have do some modifying on the brakes. Some B350 Dodge vans used a wheel with more backspacing, you could use them to narrow things up a bit too.

As far as the front brakes go. There is no definative solution yet. Grigg, myself, and some other members are working on something that will work on the 3/4 and 1 tons. I would definately hang on to the master cyl. and booster, you may be able to do something with it later.

Chris

BTW, I have a 67" full float and a 63" full float. Check out the pictures at www.photobucket.com/whitedog76pics