i have one in my fiesta and its running just over 300 lbs, but mine bloody broke, part of the lay shaft and the pinion is broken, waiting to see wat happens, my gear box is at cts at the min, its going to cost me over £800 to fix, my box is the stage 2+.

so really, i dont think it can take 300 lbs with huge abuse but having said that my car used to run 341lbs and it did not break then.

i think its down to the way you drive it if you just plant it and dont take your foot off the gass wen its in gear you should be ok, thats wen mine broke, wen i took my foot off the gass