Been cold here so I haven't done much. Have been doing some more research and came across this thread.
https://ls1tech.com/forums/automatic...turbo-car.html in particular post #6 put up by one of the 4l60e guru types. Lists how he would set up a bunch of different things. Lots of good info in the thread.
Post #6
To get this to hold up for high horsepower. Use Torlon checkballs. If you are using a new separator plate you will have to make a new seat for the Torlon checkballs (this is easy to do) as the Torlon checkballs take forever to create a perfect seat. Block the 3-2 control valve inboard, then when using the Sonnax 2nd apply servo you can drill out the 2-3 shift feed hole to .155" and the band release hole to .104". When using the Corvette servo, again block the 3-2 control valve inboard, then you can drill the 2-3 shift feed hole to .135" - .140" and the band release to .099" - .101". The Carbonite extra wide 2-4 band with a new oem drum is a good idea as suggested. Run the minimum band clearance. Set the 3-4 clutches at .025" minimum and .040" maximum. 10 vane rotor with the 13 vane slide. Install the slide/rotor at .002" minimum and .003" maximum clearance to pump body. Use the TransGo steel rings and "single" hi-rpm slide spring to keep the pressure up (flat) to apx. 8,000 rpm. I sometimes use the 7 vane setup with the 13 vane slide on motors going over 7,200 rpm for a faster pressure recovery. Install the reverse abuse plug or plug and valve assembly from Sonnax as suggested. Leave the reverse/input piston alone "no restrictor" in the aluminum piston. I have never had a checkball capsule in the input drum present a problem when using the correct hole sizes in the separator plate. If you want, block the checkball capsule completely and add a .035" hole at the bottom on the input drum just below the outside seal area on the 3-4 apply piston. This will stop any centrifuge from trying to apply the 3-4 clutches at hi-rpm in 1st & 2nd gears. Use the TransGo 7-CS clutch spring kit here, as this helps keep the 3-4 clutches off at hi-rpm in 1st & 2nd gears also, and makes for a cleaner and faster 3-2 downshift. Add the "white" actuator spring to the actuator valve from the TransGo Shift kit. This raises line pressure apx. 5-7 pounds. I prefer the TransGo .500" boost valve, however the Sonnax .490" boost valve with or without O-rings work ok too. When all is said and done, install a 0-300 psi. pressure gauge and see what the readings are at WOT at 4,000 rpm and higher. The pressure should be 235 - 245 psi. If lower you will need to address the EPC solenoid to get the correct pressure needed here. If higher, remove the white actuator spring if installed or you will need to address the EPC solenoid to correct this. This rarely happens too much pressure. Lower pressures are common and will hurt the 3-4 clutches before it will hurt the 2-4 band, and higher pressures can possibly cause parts breakage. If you have a very good 60 foot time, put the pressure gauge on it and make sure that it is not picking up air. This will be seen most on the 2-3 shift and the pressure gauge needle will fluctuate wildly. I use a Borg Warner Hi-Energy 10 clutch setup in the 3-4 setup with the stock input drum and an 11 clutch setup in the Sonnax input drum. There is more, however this should help a lot here.
Also came across this
http://4l79.com/?page_id=161
Pretty nifty setup to get way more clutch and steel surface area in the 3-4 clutch.