Hey Weeds...
What exactly is the "Andereggen/Joyce IFS swap" ?
I googled it and didn't come up with much of anything.
You might do better googling Andereggen separately. Joyce is too common a name to return usuable results and coupling them together probably excludes hits on either of them, while the published stuff is generally one or the other.
Both are names associated with swapping the IFS crossmember of suspension from a '63 to '87 Chevy/GMC pickup to an AD pickup.
I think you'll find links to one or both of these in the Tech Tips here or referrenced in other threads here.
Andereggen is often quoted on this swap, but he was never happy with the end result and planned to go back stock on his truck. My understanding is he has since sold the truck without completing it.
