I remember some discussion of VSS necessity on the '7747 on CK5 some time back, and most without VSS were adamant that the '7747 just didn't need it. Until recently, I had no experience on the '7747 to comment. Now I do. From what I found on my Dad's setup (mild 454 build w/'7747) if something else is wrong (such as his IAC adjustment) the problem is compounded when VSS isn't present. His truck would stall nearly every time the clutch was depressed when coming to a stop. Hook up VSS, and while the IAC problem didn't go away, the truck no longer stalled. Obviously fixing the IAC is the solution, BUT when something does go wrong, there is no failsafe if everything isn't in place.

I understand the DRAC isn't for every application, but I highly recommend using it for the '73-87(91) series trucks if at all possible. There are enough of the '90-91 variants out there that the parts required aren't too pricey. 205's are a bit more difficult, but the parts can be had. I believe someone even did some work to a 241 reluctor to get it to fit on the 205. I wouldn't be surprised if some of the S10 t-case setups wouldn't also be potential donors.