Not sure witch one to go with;I like top end but also like a good launch off the line but this car is driven daily also so Maybe even a 3.08 or 3.23?

 

Id go with the 3.42's, thats what I just got, and I absolutely love them. the laucnhes are incredible now, and Ive been to about 130-140 with about 1000 rpm left before redline, so you've still got a great topend

 

I still have the stock 2.73 in my 87ta but my 406 has taken its toll on it so I'm getting ready to rebuild it; just not sure with what gear. Some one here said that 3.23 was better for longer stroke motors...

 

3:42 is the best all around gear for street!!
SSC

 

If you cruise mainly in town 3:73s with OD aren't bad. If you do a lot of highway driving at highspeeds 3:73s can be a little much with OD. 3:42s are a nice compromise. With a 406, I would think if built properly there should be enough torque off the line, so traction might be a problem and 3:73s wouldn't help much, I'd go with 3:42s.

 

It all depends on what cam you're running in it. I've got a xe268 in my 77 T/A with a 400 + .030 pontiac 323 gears, t350. That car is a lot heavier than a 3rd gen. I've out run a 2000 T/A and 2001 SS camaro, to a 100 mph. I'm going to find out how it compares to my GTA this summer, as the 77 is in bed for the winter. I would think if you're using a 700r4 trans, a 323 gear would be plenty. But then again you have to consider where the motor is making the hp, and torque.

 

3.42's are the only way to go......:lala: :lala: :lala: :lala: :lala:

 

Thanks for your opinions...I'm running a t350 so no od thats why I thought the 3.23 would be my best bet since already spend enough time at the gas pumps.Guess I'll have to make a decision.Just hate to put a gear that spins off the line and no top end.:hail:

 

cp87GTA you have 77ta with a 406 big block? Mines a 406 small block chevy.

 

Some people call the Pontiac engine a big block. All Pontiac engines are the same size out side. No big verses small. Anyways your 400 small block is the same bore and stroke as my indian block. Tourqe should be close, depending on cam choise. My 406 likes shifts in the 5700 range. I'm running a 350t and a 323 gear in it. If you drive on the highway much, anything more than a 323 will drive you nuts. I drove to St.Louis to the pontiac show last summer, cruises at 2800 at 65. I'm thinking about puting my 241s back in that car. Gas milage went down from 18 to 13 by changing to the 323s. od is the only way to go if you want your cake and eat it too. I think you will have a tough time keeping tires on it if you go to a deeper gear set up.

 

Hey thanks for the input 87gta, probably go with the 3.23. I'm running a mild cam in my car no big lift on it and no stall converter. The 2.73 thats in it now is not a bad gear just a little boggie in the lower rpms. I mean don't get me wrong I can still smoke the tires off the line with my setup but cruising between 2-2500 and then going to full throttle seems a little slow till I get in the higher rpms. This is probably were the 3.23s would make a difference for me than the 2.73s and hopefully won't be a big difference in gas consumption.

 

I drive a Camaro with 3.73 gears and do quite a lot of highway driving. Is this bad for the car or will it just burn gas? What are the advantages/disadvantages to putting the stock gear back in? Also, will having this gear in make the spedomeder show a higher of lower speed that the car is really traveling. Thanks.

 

I have been through 3 rears this summer.....don't ask......stupid c clips and pinion bearings! Anyway....I like the 3.42's with my 700R4. I found that the 3.73's killed my top end and I have the synonomous drive shaft vibration and that put it right in my cruising range. The car launches hard with the 3.42's and I found the 3.73's made a lot more spin and a lot less go. I would go with 3.23's or 3.42's. For the other guys.....3.73's won't hurt anything but your mileage. They work great but they suck if you don't live in the city. They killed my gas mileage and top end.