Our 850cfm 4150 holley carburetor has been proven to 1685HP. If your looking to put together a more serious blow through program this is the carb for you. Even if you plan to still put some street miles on your ride our 850's can still help maintain exellent street manners. 

CSU starts by milling the choke tower and machining the main body for screw in air bleeds. Then all the venturis have the casting flash removed and blended for improved airflow.  After machining and blending of all venturis is completed we install our custom designed billet annular booster.  This booster is a critical part of the metering circuit.

Each base plate is hand assembled assuring a smooth transition from idle to WOT. End of primary throttle shaft is cut and base plate is capped.  All base plates are checked for WOT and throttle blade alignment in throttle bores.  Vacuum port in the rear is tapped for 1/8" pipe plug or fitting.

The metering blocks are calibrated to each customers needs. This includes modifying the emulsion circuits, idle feeds, and pvcr's (power valve channel restrictions). Secondary metering blocks also get screw in jet extensions.
Upon final assembly attention to detail is our signature at CSU. Nitrophyl floats and viton tip needle & seats are installed. The jetting, air bleeds, and accelerator pump circuits are calibrated to complete the overall custom calibration.  Only at this point is the carburetor ready to carry the CSU name.  It also comes with a money back guarantee. If your not happy with our carburetor within 30 days we will refund your money....

Our 850cfm carb has a dual needle & seat bowl option.  This is recommended for applications making over 1400HP.