Throttle Body Shop TBS 10203 40hp PU Kit 1986-95 GM TBI Motors GM TBI 40hp power up kit. Includes injector spacer (design may vary), 14psi regulator spring and instructions on modifying you OEM stock TBI base to add enough fuel and air for up to 40hp gain. Great for motors with headers, air intake and small cam upgrade Fits: 1986-95 2.8L 4.3L 5.0L 5.7L TBI motors Silverado Sierra Suburban Yukon Blazer Camaro Firebird Caprice S10 Jimmy Includes 1/4" thick injector spacer, 14psi regulator spring and instructions on modifying your OEM stock TBI base to add enough fuel and air to support up to a 40hp gain Although this kit will fit 7.4L TBI motors, most came from the factory with a spacer. Please verify before purchase 2nd photo shows what these modifications to your TBI looks like - red arrow shows spacer