I'M HAVING MY 72 GS-455 CARB (7042240) REBUILT. WHAT MODIFICATION ON JETS/RODS COMBO SHOULD I USE FOR 455. THE 455 ENG. HAS A 10.25 TO 1 COMP., LUNATI SP1- 230-245 CAM,EDELBROCK INTAKE AND STOCK EXHAUST MANIFOLDS........ VINCE
Vince, I have the same carb on my GS. It was built by John Osborne. He used 76 jets, 46B rods, and BG secondary rods. I have headers, 2 1/2" exhaust, and X pipe. Hope that helps.
vps1114, The jetting mentioned by LARRY70GS should be pretty close for your combination and it would be a pretty good starting point. Several other things must be considered with respect to secondary jetting, including hanger selection. I have a ton of 455 Q-jet customers, and this can be very critical. Give me a call if you want to discuss. My contact info is on my web page, www.holsfan.com/deano . Dean Oliver Deano's Carburetors
i see that the modified engines are running with smaller jets and bigger rods. Is this because increasing the breathing of the engine by porting, adding headers etc increases the efficiency of the engine? If so did anyone notice a mpg increase when adding headers or any other performance mod.
MPG ...whats that..???? Lean is mean.........to a point, just need to read the plugs right to prevent damage. But running too rich can cause problems also.....be carefull what jetting what someone else is running.
