Grant, the value question is more of a "older then what I have been playing with" than a "Chevy vs GMC" question. Yes GMCs are worth more to us GMC Collectors looking of trucks that have not been changed, but you'll find GMCs of this vitage are not as much the same as they look either. The reason I asked is because I have not been looking at truck of this vintage and have no ideal what thay are selling for and in what condition, but when one pops up right in your back yard as it were, then you got to check it out even if older or even the worng make.
As for your Trans question, I'm not sure, no one I know has found one yet in a truck. I have been told they are found in Diesel trucks, and milatry, but the truck I got my Toro-Flow diesel out of had a SM-420 in it....
