Okay a little about my bronco it is a 1979 it has a 400 in it that has been bored .040 over has tmeyers pistons in it. Has .020 shaved of the heads .010milled off the deak. 260 comp cam 670 holley street avenger carb Holley dominator intake. She runs great with lots of power but sometimes when I am off roads under a hevay load and come off the gas fast she will stall out. Always starts rite back up. Any ideas?