It's only been three months since I started working on the '68-it feels like it's going well so far, and I'd like to keep it that way! Most of the major chassis work is done, and the rest will be finished next month, minus the motor and tranny mounts. The Fatman Mustang II is ready for action, the steering is hooked up, and in this installment, I'm gutting and updating the rear suspension. When I called Fatman and ordered the frontend, I also got their rear parallel four-link kit and Pro Shock coilovers to complete the chassis transformation. Brent, aka The Fatman, let me drive his '67 F-100 with all the same stuff under it, and I was surprised how nice an old truck could handle! To help customers complete their suspension upgrades and get back on the road, Fatman works quite a bit with Engineered Components Inc. (ECI), which makes disc brake kits for almost everything. After discussing my needs with them, I decided on their big 13-inch disc kit for both the front and rear that uses widely available GM calipers and pads on their impressive cross-drilled 13-inch rotors. The ECI kit comes with all the brackets and hardware necessary to mount it to your rearend.
I had to do something about the old stock 9-inch rearend while I was at it, and right off the bat I knew I'd have to redrill the 28-spline axles for the 5 on 4 1/2 bolt pattern to match the front, mostly for the sake of finding wheels easier than with the 5 on 5 1/2 pattern. At the same time, I should go through the rest of the rearend since it's been in service for almost 50 years, maybe put a posi in, and upgrade to 31-spline axles so I don't have to worry about any of it ever again. I brought my rearend down to Currie Enterprises for the once- or twice-over. In the end, the only thing they used from my stock unit was the third member housing since it's of the strong, post-'65 variety and is good to around 450 horsepower. They stuffed it with a posi and some 3.50:1 gears. The rebuilt third member was dynoed and dropped into their 100 percent new 9-Plus Hot Rod housing that also holds their new 31-spline axles and roller bearings-done.
To get started putting all this together, the bed needed to come off, the stock rear suspension had to be removed, and the crossmembers just in front and behind the rearend had to be taken out. With the truck up on jackstands and leveled, I soon had it stripped to just the cab sitting on the frame. Next, I cleaned and boxed the rear framerails, and with the bed back on, I found my rear axle centerline where the wheels looked best in the wheelwell at my projected ride height, which is a half-inch lower than when the frame sits on the rearend housing with 27-inch-tall tires. With all this coming together, it was four-link time. Patience, careful measuring, and planning are the most important things here-if you rush or fudge something, it'll show in the end. I want my truck to sit lower than most, which forced me to improvise a little on the thorough directions Fatman includes, but it worked. Next month, I'll weld everything up, step-notch the frame, finish the upper coilover mounts, and install the panhard/Z-bar, and it'll be a rolling chassis! Getting all the coinciding parts together, like having the finished rearend and brakes, helped avoid any possible problems down the road. All the companies involved have very helpful tech lines with professionals ready to help if you get stumped, so follow along, and we'll see you again next month!
