I was never uncomfortable with the E model. I ran one 450K and had 1 problem with an injector tip at around 30K. It pulled like it was supposed to. Set at 500, it would kick the fuel off on a cold day when you first started out if the boost got above 40 in if you were pulling a load. I was at Dallas Pete and never saw a C model when we were looking and they had at least 60-90 trucks on the back lot. Most were pre delivery but they sold them there. Tried to get me to take a Rose colored one but in 94 I figured someone would suck the chrome of it.
I called about the truck. It was sold. The ad was wrong about the 3406B....the guy on the phone said it was a 3406E. It's hard to fool a bunch of hard core TTR guys.