Holley Main Jets (2) - 84 NG21 500" shafts

500" shafts

Big Block Crank Snout

Elongated (dual pattern) mounting holes allow fitment on intakes with square flange (Holley 4150 style) or large flange (Holley Dominator style)

Engine Side

Stock Car type and square window nets for full-bodied cars

Holley Main Jets (2) - 84 NG21 500" shaftsSet 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