Try jetting the carb. up enough to slow the car down in the 1/4. I had a similar problem with a Holley 850 DP, list # 4781-7, my car ran 10.32 at 129.7 MPH with .110 neeedles and seats in it I had treid jetting it up two jets sizes at the local 1/8 mile track and it didn't respond. I ended up changing the needles and seats to a set of .120 and tha car pick up .2 ET and almost two MPH at the local 1/8 mile track(2500 Ft elevation)I took it back back to the 1/4 mile track at Woodburn this last weekend (180 Ft. above sea level) with the same jetting as before the needles changes and the car slowed down to 10.44 at 126.03 MPH MPH I have a wideban on the car, it had shown that the car was going lean a little at the end of the 1/8 mile and really lean in the 1/4, the changes verified that is was starving for fuel, not enough to make the car nose over or miss, just not enough fuel supply to not respond the the bigger jets I did change the jetting back down two sizes and that helped a little, it was still way to fat with the new needles and seats I will work on that carb. later, I switched the carb(1050 Dominator) and intake (domimator intake flange manifold) this weekend at the track and the car ran 10.03 ET at 133.45 MPH several times, even in worst weather