When considdering installing an OD combined with the torque tube this might give an outcome. The kit is kinda spendy but most of the work can be done by your self , i would advice to let a professional welder weld the inner/outer flanges. The install gives 28-30 % better engine performance and reduces fuel expends to. In the long term this investment is worth its money considdering fuel prices will go up in the future and your engine will long laster. If there are any better or more cost reducing solutions for a torque tube OD i would like to hear about that from you guys. Nate came up with the Rucksell compagny "truckstell" OD wich looks promising and posseble to install to the chevy torque tube. Articles about the Truckstell OD ; http://www.oldchevytrucks.com/blog/index.php/2011/02/1950-chevrolet-deluxe-ton/ http://www.chevytalk.org/fusionbb/showtopic.php?tid/175613/post/1304283/hl//fromsearch/1/ I have installed a 4 speed Saginaw transmission with the short tail peace solution from Patricks. The 4 speed has very wide ratios, which makes for a very nice gear spread with the overdrive unit splitting gears. http://www.gearvendors.com/ Here are the ratios: 1st- 3.11 2nd- 2.20 over- 1.71 3rd- 1.47 over- 1.14 4th- 1.1 over- .778 Your 3.55 :1 axle ratio in overdrive drops to a 2.76 on the highway. Torque Tube Kit one sheet. The installation of our torque tube kits are very straightforward. The kit is supplied with two flanges on the overdrive itself and two mating flanges with the same bolt hole pattern and centers are supplied for your mechanic to enlarge the centers to fit your torque tube. The internal driveshaft couplers are supplied with center bores for your mechanic to enlargen to the same as your shaft size and weld in place. In basic terms the process of installation is as follows. A) Remove the torque tube from the sphere end at the transmission and mark the position of the internal shaft relative to the torque tube length (how much does the internal shaft stick out beyond the torque tube measure presicely). B) Mark the tubes 12 o:clock position - so you know where up is and can position the overdrive so it looks exactly correct and is not canted off a few degrees. C) Pick the spot in the torque tube that you want the overdrive to sit - before you remove the torque tube from the vehicle - you want the overdrive as far forward as possible without the up and down movement of the suspension carrying the overdrive into the floor or tunnel. The only benefit to keeping it forward is that it is more out of sight and has less impact on sprung weight (the closer to the diff it is there could be some stiffer ride over bumps as the torque tube moves more at the diff than at the trans and will now have the od weight as well to move). Having said that, we have never had a customer notice anything but better ride quality not less. D) Now you are ready to remove the torque tube from the diff and mark it up for the length (flange to flange) of the overdrive that you will cut out of the tube - and the length coupler to coupler of the internal shaft modification (remember that you internal shafts will go inside the couplers and be welded there so allow the proper depth. E) Weld on the flanges to the torque tube being sure to get the bolt pattern correct for 12 o:clock. Weld on the internal couplers (orientation does not matter here) it should be that your internal bore size of the coupler is almost a press fit so you get a good true running shaft - check total run-out with dial indicator before welding in place. F) Mount the torque tubes to the Gear Vendors and slide in the internal shafts and then mount to the diff and sphere to complete the installation. G) Electrically the overdrive can be activated with 6-12v direct to the solenoid. You can either use our manual switch assembly or any latching switch you feel looks good in the car. Many classic owners prefer to put a switch on the dash that matches the rest of the vehicle knobs (ie: a push pull switch) and that does work fine except maybe when splitting ratios and moving the shifter at the same time (as in going from 2nd over to 3rd direct). You can put the green lamp we supply on the shifter circuit – just do so in parallel not series. In other words run your ground to one lead of the overdrive solenoid and your 6-12v to the other lead of the solenoid through your switch. Now hook the light up to the ground and then to the lead of the solenoid after the switch. The 2013 price of the kit is $3195 + $55 shipping costs. Martinius.
Martinius, Many, many years ago I made an overdrive set up for the torque tube Chevy trucks. I used the front half of the 3/4T torque tube to bolt up to the transmission and had an aluminum case cast that accepted the old BW overdrive unit. There was a support bearing in the front to support the rear of the driveshaft which had been splined the same as output shaft of a regular OD transmission. A regular U-joint fit the back of the OD with an open shaft to the rear as was standard on 3/4T AD's. The whole works bolted up to the factory hanger bearing holes. On 1/2 ton trucks you had to fabricate a crossmember to mount the unit on and I ended up making the 3/4T crossmember more rigid. With the 4.56 rear gear in the 3/4T it ended up being 3.19 in OD. It worked well but was just to darn expensive for the 1960's economy. This set up in our 1953 shop truck with a 327, cam, headers, and a Holley THREE barrel carb was waaaay too fast for drum brakes and skinny bias tires. I still have (I think) the pattern for making a mold for the case but it gives a rough casting that requires lots of machining.
