B/PS lt1 formula

[ss3011]

While the spline count is the same, at 30, there are differences in the turbine shaft. The majority of the 700-R4 transmissions used a "298 mm" torque converter. The turbine shaft has a stub and an o-ring on the end close to the engine, the splines are closer to the transmission end. Most of the car transmissions used that combination, even the early LS engines. The trucks with LS engines got a "300 mm" converter. The turbine shaft has the splines closer to the engine end and a journal and o-ring between the spline end and transmission. The basic converter to flexplate spacing is the same between the 700-R4 (4L60-e) and the 350/400 THM transmissions. The later 4L60-e with the 300 mm converter is different and would require a different flexplate , and a spacer for the crankshaft to converter pilot.