The 3000 series trucks are the smaller trucks while the 4000 series and up starting with the 1-1/2 tons are the larger wider trucks.
I can't really see using the wide front end with an S-10 frame simply because the S-10 tread width is already too narrow for the 3000 series front end. Maybe if you are going to run some 20's that are ten inches wide. It's all about the look you want when you are done and if it looks right to you that is what counts.
Hoods have to go with the fenders because they are quite a bit different but the big truck hood has a better slope to it. Grill bars will swap but you have to use a bar for the exact position you need it for. Each bar only fits in one spot in the stack.
You have to look close but just to the right of the center bar you can see the notches in the back of the grill bars that show which spot in the grill they go in.
