[robnolimit]

Lets talk about CASTER. Caster helps your truck turn, and stay straight. It's sort of like "rake" on your bike. This "rake" is the line through the center of the upper and lower ball joints, as viewed from the side. "0" caster would have the upper and lower ball joints directly level - up and down. If the upper ball joint is in 'front' of the lower, this would be "negative" caster, and we don't want that. As the upper ball joint is moved 'back' from the lower, that creates "positive" caster. - that's a good thing. Now, for '59 and older trucks, this means you need to look at the IFS kits your using/thinking about. Those who are still making IFS kits with 1* or 2* of + caster are stuck in 1979, and that 15" is a big wheel, - and a 60 series is a wide tire. So, ask them before you buy. If you already have one, and it tends to "nose in" to a hard corner, your best bet is a custom upper A-arm to move the upper ball joint back. If your interested in this type mod, let me know, and I'll put up some info. For '63-'87 trucks, if your working with the stock stuff, it may be a bit of a different choice. These trucks already have the wheel too far back in the opening. So, moving the upper ball joint back wil make things worse. I know that Porter's Dropmember & arms address this, as do Ride-Tech, and Hotchkiss. But all of the others that I have tested seem to be on the stock geometry plan. (Before you *****, if I didn't mention your parts, and you think they are better than others, contact me with the info) Noting the wheel placement issue, the answer seems to be to move the lower ball joint forward - appx 1 1/4" would be nice. So, aftermarket A-arms, or modify stockers.I'm going to modify a set of lower arms for our '72 JT next week. I'll put up some picts and show you what I've done.