you can compensate for the rather large change in rear gear ratios (2.41:1 vs 3.73:1) roughly a 60% change , in the way the engine rpms to ground covered per, tire rotation, with a manual transmission and changes in driving styles but a change that drastic with an automatic transmission is sure to work FAR better with one of those ratios that the other.
you'll definitely find you'll spend a gear deal more time between gear shift points with the 2.41:1 rear gears , and rarely see the car reach the upper range gearing during street driving.
btw buy new differential gears, not used ones, those are a Risky buy,
if these gears were run with poorly set up tooth contact pattern,
you will inherit noisy gears, no matter what you do.
have an experienced shop or mechanic set up the rear gears,
if they are not correctly installed they will be ruined or at least noisy
in fact your differential can differ just enough, dimensionally,
to cause new issues to come up with previously run gears from a similar differential,
that worked ok in that differential
READ THE LINKS AND SUB LINKS
http://garage.grumpysperformance.co...late-gear-ratios-and-when-to-shift-calcs.555/
do a few calculations, think about the rpm band
YOUR engine makes its best power in,
and YOUR tire diameter
and YOUR cars weight
and YOUR rear gearing,
and YOUR trans GEARING
as a general rule if your looking for brisk street performance,
(especially with an over drive transmission)
youll want the transmission first gear . multiplied times the rear gear ratio to fall in the 10:1-10.6:1 range
and youll want the engine to cruse at 70 mph in the lower end of the engines effective torque curve, If you take the time and effort to do all the math and accurately match the rear differential gear ratio, transmission gearing and tire diameter youll eventually find a clear consistent advantage to use of a transmission with an over drive top gear ratio of near .70-.75 in most cars and a rear gear ratio in the 3.73:1-4.11:1 range for performance cars.
http://garage.grumpysperformance.co...late-gear-ratios-and-when-to-shift-calcs.555/
http://garage.grumpysperformance.co...r-gears-at-the-transmission.12179/#post-59006
http://www.wallaceracing.com/gear-speed.php
http://vexer.com/automotive-tools/speed-rpm-calculator
https://www.summitracing.com/expertadviceandnews/calcsandtools/gear-ratio-calculator
http://spicerparts.com/calculators/transmission-ratio-rpm-calculator
http://www.differentials.com/technical-help/differential-gear-ratio-calculator
http://vexer.com/automotive-tools/1-4-mile-ET-HP-MPH-calculator