A couple years back I decided to move away from toploaders as a means to get my Fairlane down the track quicker. To me that meant either a G Force or Jerico was the next logical step. Ended up having a gentleman from TN build me a top and bottom loader Jerico box with a. 3.19 low gear. I loved trans at the track but on the street I could not easily shift into fourth. It would go but I would have to bang it like I was at the track. This was a little disappointing because on the street the trans would pull into second or push into third without the same drama. Techniques tried on fourth, double clutching, rev and drop rpms but it would grind unless it was banged in.
Along the way I had the opportunity to buy a low mileage DR4-4 box with a 3.08 low for a very good price. The box was ordered originally for a SBF so it had the longer, 26 spline input shaft. My clutch is a Ram with a 10 spline disc. I thought I might swap discs but decided to keep everything here to work with the 10 spline. Also, the additional length of the splines on the small block input can get close to the disc in a big block environment. That meant shopping time for a big block 1-3/8 x 10 input. I picked up a few but they were not Revision 4 friendly. In the end I bought one from Jerico, ( might be the last one Scott had).
With helpful advice from Bob Treadway I was able to swap input shafts without complete disassembly of transmission. It’s tricky but can be done. The mainshaft and cluster were not moved. That is really the point of this post, to let others know the swap is manageable.
Also want to give some props to Rory McNeil for invaluable advice along the way.
