With the exception of the GMC wrecker, the Revell kits are all '77-'78 model year. The stepside trucks are an aftermarket California Stepside bed, not factory fenders. The GMC wrecker kits are actually a '79-'80, not a '77 as labelled on the recent reissue.
A little late but to add to the asphalt conversation, speaking from a civil tech/inspector role I would definitely not approve of asphalt being laid down out of the truck like that. Unless it is strictly for patch work. Usually you dump the asphalt in a spreader that mixes and heats it up somewhat. For highway mixes a transfer buggy is used that has an internal hopper so that there are no cold joints in the road, just a steady stream.
Here are the Blazer's wheels and center caps painted:
Here's the Blazer's interior tub:
You can see my attempt at flocking that failed horribly. Decided to give it and the Jimmy both a black vinyl floor, which seems better suited to a convertible truck anyway. The Blazer has a three-speed column shift, had to add the shifter and turn signal lever to the steering column. And here's a somewhat successful experiment for underhood insulation. Painted some masking tape and cut to fit. Should've cleared the tape and the underside of the hood as I had to touch up the paint.