I have a 1989 Chevy Blazer K5 that my ex boyfriend rolled I want to fix it up and make it nicer, faster, and more powerful. I want to know if I should Start with the interior or the exterior first?

 

Engine make it powerful first then the exterior then the interior but that's just me

 

Start with the engine. If there is something unfixable with the body (ie busted frame) you wouldn't have sunk a whole bunch of money into something that should just be scrapped. Beef the drivetrain first. You can always transplant into another K5 carcass.