Chris, you are seeing the differences in pricing. It's good you are thinking and checking to see what's best at what price. It is nice to have a prewired kit with an inside-the-cab modern fuse box. But that is just my opinion. Maybe there is one that is affordable.
This AAW kit seems pretty nice, says extra length wires, has some extras and they use GXL wire. Free ship. 5 Stars, 21 reviews. Price seems very reasonable. AAW, best off the self kits in the business, bar none.
This is a "Hot Rod" or "Universal kit". They are always less expensive than an era correct, factory fit style kit. Your truck will never know. I am not being pushy just helping search. I realize what you said about farm truck and such, and I do understand. I appreciate all teachers and their commitment.
