Almost all converter manufacturers provide recommendations using combinations proven with various applications and several basic charts and ratios. As with most performance parts, torque-converter recommendations are determined after learning what each specific combination is, and this process cannot be patterned solely after a formula. When choosing a torque converter, it's very helpful to know how much horsepower and torque your engine is producing through what powerband. You may want to have your combo dyno-tested first so that you can provide the manufacturer the results.
Q&A With Paul Darden Of Jet Performance
CHP: Are there benefits to running a 700-R4 or 200-4R overdrive with a non-lockup converter instead of the traditional lockup converter?
Paul Darden:
Yes, you can modify these transmissions so that you don't have to run a lockup converter, then it won't require any additional computer controls. For instance, you could then easily install one of these overdrive transmissions into an early Chevelle, Camaro, or other noncomputer-controlled vehicle.
CHP: What modifications need to be done to run a non-lockup in the 700-R4 or 200-4R overdrive automatic transmissions?
PD:
The pump is changed by replacing the lockup valve with a non-lockup valve from Transgo and removing the check ball on the end of the input shaft, which eliminates the lockup feature. Fuel-mileage changes are negligible, and then you can run a non-lockup with no wiring.
CHP: Are there any special procedures you should perform to lube a converter before installation?
PD:
When installing a new converter, you should set the converter on a bench first and pour new transmission fluid into it. Most converters will take about 5-10 minutes to accept 1 to 2 quarts.