72mm Throttle Body and power 6 Plenum This is a NEW AND IMPROVE "GN1Performance BILLET ALUMINUM 72mm THROTTLE BODY AND POLISHED UPPER PLENUM" for a 1986 or 1987 Buick Grand National, T Type, Turbo T, or GNX 3.8 liter turbo V6. With this throttle body and plenum kit you... MSRP: Was: Now: $589.00 Choose Options