Hey Dave, sorry about your explosion. Hope it didnt hurt the car like Kyle's did.. Rich will let you run a single 850 if you want and you can still run with 422. won't be as fast, probably, but you could at least get out this year. we have the cavities in the sides filled in to prevent puddling, we think that's the main source of explosions in these manifolds. I have the same pop-off valves as you as well, but i do have 2. I hold the throttle open a bit when i start it also..