I was running a 990 Carb on my stock motor the only hop up is a CPI pipe,the 990 Carb stoped pumping gas,I went to Gizmos web site shopping for a new Carb and found this one Version 2 GZR big bore WT-771,finally got it on and what a difference it made,better throttle responce,and made the truck scream, if you need a Carb should look at this Carb.