Originally Posted by
randyr
Hey Spikeo, Welcome!!
I just read somewhere that the Jag IRS is around 61" wide from each wheel mounting surface. I know the 41-48 Fords are wider than the 35-40 Fords but I don't remember how much. I have a '58 Ford 9" rear in my 37 Ford sedan that is 57.25". Given the difference in width between the two cars (37 & 48 Fords), I don't think the Jag rearend will give you much of a problem with wheel offset.
Are you going to use the Jag IFS on the front, too? I read a few posts on another forum where they were using both the IFS & IRS in 48 Ford pickups. I think the car & truck frames are different by then but in either case, they said for the Jag suspension to give proper handling & ride, the frame itself must be very stiff & rigid. If that's true, you'll probably need to box the entire 48 chassis and maybe stiffen the X-member some.
I hope somebody comes along soon who has some actual experience with this swap but there's a little bit to chew on for now. Keep us posted. sounds like a fun project!
Randy