Richard Daugird

I don't really see the purpose of changing transmissions except to get overdrive, which you don't need with the weak rear gears. Changing them would be the first thing I did, PERIOD, if it was my car. Even without overdrive, I'd want 3.55s. It would feel like adding 50 horsepower.

Sky65

I respectfully disagree. Changing the rear to a 3.55 is a compromise. It would provide better 1st gear pull away than the 2.72 but not the best and sacrifice a good hwy cruising gear for an OK gear. Installing a RG non-OD trans will have a better 1st gear ratio than the 2.73 and 3.55 and keep the hwy cruising gear. Also no big drops in rpm between 4th and 5th as many OD trans have. More of a close ratio 5spd.

RG
3.27 1st X 2.72 rear = 8.89 Overall

Muncie M21
2.20 1st X 3.55 rear = 7.81 Overall

Just as a reference point, M21 with 4.11 rear
2.20 1st X 4.11 rear = 9.04 Overall

RG 1st gear overall ratio/M21 1st gear ratio = comparative rear gear Ratio
8.89 Overall / 2.20 1st gear = 4.04 Rear ratio

So RG trans with 2.72 rear would pull like an M21 Muncie and a 4.04 rear and maintain the 2.72 top gear.

What's not to like?


Tom

Pop Chevy

Have you thought about a T-5 trans ?

John 65

Love mine... and with a set of 3.70 rear gears its the best of both worlds.

OldCarBum

You should go online and do your research using a good gearing calculator and not guessing. Every transmission on the market offers different gears and you can calculate engine rpm through every gear, at any given speed. You want to keep your gearing so your engine rpm is within a usable range. To low rpm on the highway at 70-75 may cause your engine to bog and you my never be able to use your top gear' or you may have poor performance off the line. I have a 454/TH400 with 3:36 rear gears. At 70 I'm turning 3071 rpm. I'm swapping to either a TKO600 or 2004R which will drop my rpm to 2047 at 70 mph. Off the line gearing will be improved, as will all the in between gearing based on what I plan to use my corvette for. For example, if I hold the 2004R in third my rpm will be perfect for winding roads. Most important, decide what type of driving you plan for your car. If you enjoy driving twisting roads, flat open highways or using it as a daily commuter, these factors should be dictating your choice of gearing, and not just your final rpm. What engine mods, if any are in the future. Operating your engine within optimum engine rpm (I'm not talking peek torque or hp) is just as important as choosing gearing. You want to design your gearing to work with your stock or modified engine within your driving parameters. Here is a link to a great gear calculator http://tri-5.chevyrides.com/rpm.php