After suggestions from Tech1 and Henry I have been looking at 700R4 transmissions and to my surprise the lowest units nearest stock as just rebuilt stock units are rated at only 275-300 H.P. which should be easily exceeded with a 383 SBC. I have looked at the Raptor Jr. the Megamonster and the Bowtie Level-2 units and it would seem that you will have to go to more than just a rebuilt stock unit for a 383. One other factor is that the Megamonster unit has a totally hydraulic lockup for 4th gear while the others use an electrical switch for the lockup. Then to my novice surprise and dismay I cannot use my TH350 torque converter with the 700 R4 so you will need to purchase a new torque converter and that brings up the usual question of what stall rpm do you want to use. Let me do a slight hijack and ask others about whether the stall rpm needs to be less than the 4-to-3 downshift? For instance with my tires and a 2.79 rear gear I might be in 4th gear as low as 1580 rpm, so if I use a 1650 rpm stall converter will I get immediate "slip" when the lock comes off the 4th gear and the trans drops down into 3rd? The guy at MegaMonster said it doesn't matter if the converter stall is above the 4th gear cruise rpm because of the lock but I wonder? I am just wondering out loud but I guess the motor would rev higher anyway when the 4-to-3 downshift occurs so there would be little slip. The simple question is: does the stall speed of the converter have to be lower than the rpm of OD cruise speed?

Don Shillady
Retired Scientist/teen rodder