The 2 soeed is a bit of an art takes a bit to find the groove of when to shift . It's always helped me to listen to the truck when shifting . Use the 2 speed button early like when your going from 2 high to 3 low , hit the button to low range then shift up to 3rd. 3low to high pull button up ease off or maybe touch the clutch to let everything get meshed. More you drive it you will get the feel for it and I'm with 69 cuda I only use the low side loaded for rhe most part on my 58 also.
If you dont have a bleeder trying to get going on an old system like that crack all 4 wheel bleeders top off the master let it sit and let gravity do the work for you check the master here and there topping it off let it sit like that all day or over night . Close it back off then strat bleeding it regularly. Will get you close rather then pumping it half the day.
