I have changed the interior of our '84 SWB Silverado from Tan to gray. It was originally blue but a PO changed it to tan. I was able to accumulate all of the pieces without too much difficulty. The plastic parts (kick panels, headliner trim, pillar moldings all came black and I prepped them and painted them and they look great you can't tell they were not originally gray. The dash and door panels I bought came in gray. Note that it is a little harder to find "reproduction" door panels, most you will see are "replacement" which will not use original trim. Carpet is also widely available.