27 spline 700r4

i know the 30 spline is better, but what modifications can be done to the 27 spline to make it better ? say to withstand a 400hp sbc.
the reinforced sun shell would be one i know of.

thanks, ROGER


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They had some bad internal lubrication issues up until 1987,best core is from 1987-92 as these were non-computer and had all the factory upgrades for reliability asking one of these earlier 700's to take 400 HP is probably asking too much of it,seriously you should look for a better core to base your build on.

You can turn a 27 spline into a 30 spline. You have to change the pump stator, and input shaft. I prefer later input drums, anyway, as the earlier drums had checkball sealing issues. Just get a late drum. The pump stators are pressed in and retained with 3 27 torx bolts. You'll need a presss to change it. Youll also want to swap to a later style input sprag and low/reverse sprag. Using a later drum and sprag will neccessitate a late 3-4 snap ring and a late forward pressure plate, which will change your forward clutch stack. If you're not sure of all the interchanges, it's best to find a good "loaded" later drum. You can pick up a "universal" pump stator from most transmission parts suppliers.

Frank