Well heres the problem, with a full tank I get a drop in speed when I go inverted but this goes away after Ive burned off about 1/4 tank. The real problem is it always drops way down to what sounds like a deseling idle when I do an outside loop. Keep in mind the Vstick 60 will outside loop as tight as a regular loop. If I pull it around to slow the engine will quit every time. This is the only time the engine acts up. The bottom of the carb is level with the top of the feul tank plug. I know thats alittle high but my other planes are the same and dont have that problem. however they wont outside loop near as tight as the stick, 20' loops with ease. The best way I can describe it is the engine has that din din din chainsaw idle sound just as you get to the top of an outside loop then it picks back up and goes back to normal throttle. The engine is an ASP .61 running wildcat 10% nitro 18% mix lube. And other than this one thing is a real screamer with great vertical running an 12x6 true flight prop.

Would running the fuel line down then up to the carb help?

Running the fuel line in any extra way will not help. Always go as straight as possible from tank to carb with not a lot of extra looping.
I think your engine is going a little lean in high-negative G maneuvers. In the outsode loop, the forces are trying to push the fuel towards the outside of the loop which in your case is toward the top of the plane. Since your tank is already a little higher than ideal, this makes it more difficult for the carb to draw fuel. If the tank were too low, then an outside loop will increase the pressuret to the carb. try richening the needle valse a few clicks and see if it gets better.