Yes the Carb from the VG 30 will fit .

We had a similar problem with the Losi . What we did was lower the tank . The driver had the tank up high for the larger battery . funny enough thats when his problems started.. i told him to lower it back down and the problems went away .

Its also very important to have the fuel line go horizontal from the tank to the carb.. if you have it going up and down it will cause irregularities in pressure vs gravity ..

Hope this helps !

Cheers MM

www.massivemods.com