Hello everyone, i am new here. I need a little guidance. My cousin recently bought a 1990 (im assuming c1500) 2 wheel drive with a swapped 305 (was a 350) and the brake booster needs to be changed. The issue is i have no clue what the part number is to replace the damn thing. I did a little research and started looking at the glove box sticker for the brake code and found jd5. A little more research and that seems different to what we pulled out. Its 10 1/2 inches in diameter. Any help is appreciated even if it directs me to another thread explaining everything.