Hi Bob, I honestly can't tell you what the needle setting are as we have pretty much always run Nova carbs on the XPs. We actually have one XP carb that works very well but I had to machine a fine point on one of the prototype needles they sent us to test. Adjusting a carb for a driver that drives as hard as Derek is difficult and almost impossible with a carb without the needed adjustments. We could never get an XP carb to run at max performance without the engine screaming at high rpm at idle. The best way I have found to set the XP carb is to not even use the low end needle for break-in. I run the low needle out to the point it has no effect on the engine and use only the high end needle while idling on the box with an engine heater running to keep the temp between 190 and 240. For race tuning I always set the high end needle first to the point it cleans out well at high rpm then adjust the low end and idle adjustment.

Any thoughts on the custom gas build

Give me a call. I will try to help you....615-642-5105