TRW piston id

Lift is easy on these old trucks, just leaf springs, about every 4WD lift kit company has one for this truck.
I have a 6" all spring Tuff Country to go on my 47 sitting on a 74 Ramcharger frame.
Looking at a 4 inch from skyjacker. Next month is the 4wheeldrive jamboree and last year they passed out a 30 percent off code plus free shipping so I’m curious to see if they have the same deal.