If you’re looking for a 4150/4500 carburetor that jumps right up on a tight converter and launches hard for nitrous fed engines look no further than our Billet Rated “R” Series. This carburetor come as a fully billet design (can be hard anodized black for $200.00 more) and has the fastest shift recovery on the market today. With over a decade of experience with multiple combinations, it’s a simple choice to go with. This carburetor is race track tested and proven with the latest technology. Fill out our quote form and let IRD Racing Carburetors get you the tenths of a second you deserve.