I did the math. For me, 3.42 gears and a 3400 stall converter work best in my Tahoe. Here's why: The 3400 stall gives me sub 2.0 60' times negating the need for gears. Next, by keeping the 3.42s, I can ride 2nd gear all the way to the 1/4 mile traps (on motor of course). I've found it's better to finish on top of 2nd gear (5800 rpms) than to be around 4200 rpms in 3rd with 3.73 gears or 4400 in 3rd with 4.10 gears. The shift extension of my Yank covnerter is around 4100 (with a 5800 rpm shift point). I love getting 21 mpgs with my big Tahoe so I'm sticking with 3.42s. Can't wait to test the new converter and my Thunder Racing Edit tune. I should drop well below the 14.80s I was running before.

 

tntrk53 bring your gears because if i dont like the ones amyracinhorse has i might pick yours up. i will be there all weekend. not promisin ill take yours cause i allready said i would take the gears from amyracinhorse. but just in case.
look for the black stepside with a cowl inducted pewter hood.that'll be me.ill also have my screen name up on the windshield

 

i had my converter before i got my 3.73s. before the gear change at 2000rpms i would be exactly at 80 and with the 3.73s it dropped me down about 10mph. at the track i still haven't gotten a good run with them. the only improvement i found with the 3.73s was more mph in the 1/4 mile

 

well i have the 4.10 as well and i do like the launch on stock converter but can only leave at 1200rpms ,but at 80 rpms at 2650 ,gas milage is 18.5mpg and with the 3.73 gears gas was 19mpg and at 80mph 2450rpms ,but tires only 28.5" high so if you get stall i would stay with the 3.42., oh ya with the 3.73 gears never could get them to hookup dont know why but with my truck they didn't work.

 

I agree with Patrick G keep the 3.42's and get a converter with a good STR.

I have 4.10's and a TT 3000, and if I let off the gas and let it short shift to second gear at 20 mph, then give it about 3/4 throttle,(not quite enough to shift back to 1st) I can feel the converter multiplying torque and doing the work. It performs better with less gear.

Skip the gears and get a CONVERTER

 

hmmm allready have a 2800 stall and my bottem end still sucks that is why im looking at gears to fix my problem.

 

Use this site to figure out all the mph figures. http://www.bgsoflex.com/auto.html

Keep in mind though the numbers are theoretical. They don't take into account tc slippage, friction and all that.

My actual speed is almost exactly the same to what it should be using the calculator though.

I'd go with 4.10s. Hell, there are a bunch of F-body guys with 4.10s, and they probably have smaller wheels/tires.

Just out of curiosity, why are you going 140 mph on the highway?

 

curiosity
its just an estimate, theres a long stretch of highway that is not traveled very much. no where for cops to hide but they do sit on it, and run rader for the unlucky few.
dont remember the rpms but thats what we estimated the speed cause my speedometer only goes to a hundred.

 

Here .. this might help.

I'm torn between 3.73's and 4.10's as well. I think since I have a TT3000 to put in, I might go with 3.73's so I can run 80 down interstate at/or below 2500 rpm. I just don't like the idea of cruising at 3k rpm's or so for a couple of hours.

http://www.gafba.com/calculators/ringgear.asp?mode=calc

 

2100 at 80. But.....I have 35" meats.