69 C10 l6 lack of power with 4bbl, offy intake, exh manifolds

[Option13]

Hi Everyone,

I hope someone can help me with my C10. Just recently installed a 4bbl Holley Carb 390, Offy Intake, Exhaust Manifold and it feels like I lost a tremendous amount of power. Aside from the gas pedal being extremely hard (need to figure out a better way to link it) when on the road I need to MASH the gas to accelerate.

My rochester single barrel gave me more power than this current set up. After reading many reviews, people said this should provide more power than the single barrel and smooth everything out.

Have an HEI distributor as well. Truck sounds like its running well...just lack of power.

Any help would be greatly appreciated.

Joe