As long as possible to avoid pulling the wheels front and back thru-out the suspensions range of travel....and they should not be parallel, but theoretically should intersect in a spot about the grille of the truck.
I now that the bars have to be as long as possible.. i just figured since most of us drive the same trucks i just wanted to see if everyones bars were close to the same length.
I know my lowers are 25" long cause I just redid them,but I'll have to measure the uppers,but my wheels stay centered through out.. I have a 50/50 four link.
shouldent the bars cross at the center of gravity while at ride height?...well for a drag car anyways ive nevver bagged a truck with a fourlink.. mabe the geometry is differnt to make it lay out but if the bars intercect at the center of gravity you will have the best launch.