Between my self and two friends we have four NV4500's. Two of them are behind Cummins, the other two are behind a 6.5 and a Vortec 5.7 Chevy. Two of them have the plastic hydro lines, the other two have the stainless steel lines. Both Cummins have Valair dual disk clutches. Both trucks with the plastic line have stiff pedals the other two have softer pedals. The one is a super duty swap and his pedal is softer than his 12 ram 2500.
So I guess my question is how stiff are all of your pedals? is anyone running the stainless line?
The part number I was given for a compatible stainless steel line is russell 694870.