It's a bit exciting when things fall into place-literally. With the big-block engine finally nestled into its new home and our Monster TH400 transmission happily supported by our custom-bent Fab-Tech crossmember, we had one key link missing: the driveshaft. We could have located a factory driveshaft and used that, however, with the power output of the engine and the intended purpose we have in mind for the El Camino, a stock one just wouldn't take the abuse. In reality, it saved us time in the long run. If we had found a used driveshaft, chances are it may have needed to be modified, which is why we went to Denny's Driveshaft directly.
Denny's Driveshaft is no stranger to prepping your muscle ride for twist. Denny's carries over 33 years of service providing drivetrain components such as yokes, joints, hardware, and of course, custom-made driveshafts that are pre-balanced per application. Our decision to go with Denny's was natural and the ordering couldn't have been easier. Two simple and easy-to-follow printout diagrams made the measuring a breeze. All you need to do is fill out the forms with the car's measurements and you'll have a brand-new driveshaft at your door and ready to bolt into place.
While the El Camino was still hunkered down at Fab-Tech Welding in Chatsworth, California, we took advantage and had their team help with the install since we were fortunate enough to have access to their lift. We took our time and filled out Denny's diagrams with the correct measurements. While some measurements, like the width of the rear U-joint and U-joint cap diameter were noted while the car was off the ground, measurements like the overall length from the transmission case to the flat surface on the pinion yoke was taken at ride height. Taking our time, we filled out the diagrams thoroughly and faxed the measurements in. Once the driveshaft arrived it took us a matter of minutes to lock it into place. While you may notice we are still using the factory 8.2-inch, 10-bolt rearend with the 1310 yoke (25-spline), we'll be upgrading to a 1350 in the near future. Follow along as we illustrate the steps on how to measure and install a custom Denny's driveshaft.
Quick Notes
What We Did
Measured and installed a Denny's Driveshaft for our A-body El Camino
Bottom Line
The drivetrain is now complete
Cost (Approx)
$325 & Up

Our first order of business...

Our first order of business was to print out the very descriptive and easy-to-understand diagrams, and list the necessary information with our measurements. When in doubt, be sure to call Denny's tech line at 716.875.6640 for additional technical support.

With the Elco on the lift,...

With the Elco on the lift, Jaime Voorhees and Junior Shostle began to take the measurements. To make sure we weren't too far off from our printed diagram, we tested the overall length measurement with the car unloaded; be sure to take all measurements at ride height. Also, as per directions, never use the hook of the tape measure to measure.

For a more accurate reading,...

For a more accurate reading, Voorhees used a pair of dial calipers to get the width of the U-joint for the pinion yoke. Since our pinion yoke had the two locating tabs we measured between those two tabs to get our 37/32-inch width.

To achieve the output shaft...

To achieve the output shaft distance, again Voorhees used the dial calipers. We measured our output shaft, which sticks out 5/8-inch from the transmission case. Note: Compress the seal if necessary.

For the overall length measurement,...

For the overall length measurement, we first turned the yoke into the horizontal position. Then, we set the car at ride height by utilizing a pair of jackstands under the rearend housing, allowing the chassis to rest on its own weight. From there, Voorhees and Shostle ran the tape measure and got a 615/8-inch measurement.

After the measurements have...

After the measurements have been taken with both Diagram B and D filled out, it's only a matter of faxing the sheets to Denny's. Once the tech department gets the information, they build the driveshaft based on the supplied information, so check twice, maybe even three times, to make sure you're spot on. One signature difference when you order from Denny's is that they balance every driveshaft at high rpm for any unwanted vibrations, whereas most other driveshaft facilities will only spin their shafts at a significantly lower rpm.