Makes sense, in that I'd suspect that whomever is in charge of the calibration for those carbs probably isn't told the intended application is 500 cubes making 600++ HP. Yeah, the bigger engine would create more signal than the carb was originally tuned for, whereas a too-big carb would need to be richer to crutch the lack of signal. [/quote]

Spot on Brad , the too rich I encountered with the Modman and 440ci . Seen it a few times on the dyno , raw fuel/black smoke but AFR showing lean .

Tex [/quote]

NO outta the box carb will be ideal for YOUR application at least not any that I've heard or seen.....