i had the 3gsk and last weekend i upgraded to the 4... pulls a lot harder and is a lot more fun to drive, but falls on its face at 3500, it will pull all the way there then just hits a wall even when free reved. should i try to tighten the springs one more click? my fuel pressure is ok and i also changed out my dv's but not 100% sure exactly what they are, they came out of a john deere they say 105 on them but im sure they are as big or bigger than a 191. the ring at the top is smaller than the 181's, and the slots travle higher up the valve than the 181 and they are the same diameter, but anyway should i try to play with the spring tention or do i need more fuel to get the revs?

 

Tighten it up and see what happens. I've heard numerous times to tighten them until the rpm's start to hang, then back it off a click.