Holley Main Jets (2) - 68 122003 and provides superior exhaust flow

and provides superior exhaust flow over factory manifolds to let your 351 Windsor block engine breathe better

2007-2018 GMC Sierra 1500

75 " Bore Size

we strive for perfection on all of the products that we manufacture

Holley Main Jets (2) - 68 122003 and provides superior exhaust flowSet of two carburetor main jets. Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors powered every NASCAR Cup team and nearly every NHRA Pro Stock champion for four decades. Now, Holley EFI products power these cars and are dominating the performance world. Holley products for GM's popular LS engine are dominating the LS scene as well. Holley's products also include performance fuel pumps, intake manifolds and