With the weight of the truck (just like 8.5's not working in trucks very well) a decent car tranny *probably* won't hold up well in a truck application. They did put car trannies in the '81+trucks, appear to be Saginaw 4 speeds, which are POS's anyway, for hard use. You'd probably end up having to go with a pretty stout car manual tranny, and those aren't real cheap.
You are right, the 465 gear spread is not made for racing. Check the NV4500 out. I'm assuming they could be had in 2wd variants, (never looked) and could be had without the super low first. I'm not going to go look the info up, (because I've made my mind up, the expense isn't worth it since I don't need OD) but I thought for sure the non-granny first gear NV4500 had much friendlier gear spacing all around, not the 6:1, 3:1, 2:1, 1:1, .7 something:1, that the "desirable" 4500 had, that the 465 shares, minus the OD.
Obviously that gear spacing is kind of made up, but its close enough to correct, the 465 and 4500 with low 1st have the gear ratios spread too far for "competetive" street use.