On the same dyno with exactly the same atmospheric conditions changing from a 4.10 to a 4.88 will show a few less H.P. at the wheels because your using some of the H.P. to accelerate the entire rotating assy at a quicker rate.its just like on an engine dyno if you go to full throttle and hold the engine steady at say 7000 rpm and take a reading then run a sweep test at say 600 rpm per second increase as it passes 7000 and takes a reading it will show 10/15 H.P. less than the steady state test because of the power being used to accelerate the internal engine parts.on the strip the lower gear may help you because the engine will get into the power band quicker after leaving the line.Bill