hey everyone, im new and need help. my cars a 1988 mustang gt, its supposed to be bored to a 308, stock intake, edelbrock performer rpm upper and lower intake manifold, stock fuel system, and bbk long-tube headers and full 2 1/2" exhaust with american thunder mufflers, smog pump and a/c deletes.... and i recently tried putting on a 70mm throttle body, and it wouldn't run. it would start and act like it had a vacuum leak and then shut off, but i'm 99% sure there's not a leak. so i put my stock tb back on and it runs fine. am i running too lean? and if so, what do i need to do to fix it?