results of my gear swap

[Joe]

well this weekend I installed my 3;73's, (originally had 3:08's)
I went to put the Auburn carrier in and they sent my the wrong one, it had 28 splines, I needed 30 splines. So I put my factory g-80 back in.
I got my pinion depth, and backlash set perfect, Bolted up my lpw diff support cover, and made spacers so that my rear sway bar would fir without hitting , filled the fluid, and too it for a test trive.
And...............I HATE THE GEARS!!!!!!!!!!!!!!!! I mean I absolutley love the accelleration, but I hate the highway rpm. At 55mph I am at 2100rpm, and at 70 mph I am at 2900rmp. This absolutly sucks.I dont reccomend this to anyone, If anything go with a 3:42 if you have a 5 speed.
I guess I wont be doing any outa state traveling
Nick

[JROD©™®]

wow...good to know man...i don't have 5 spd..but still...

[XxInFaxX]

i have the 3.42s...55 i turn close to 1600? maybe a touch higher. but not no damn 2100. wow.

[Joe]

i have the 3.42s...55 i turn close to 1600? maybe a touch higher. but not no damn 2100. wow.

How come you park at the end of your driveway??? Also Did you see me come through you track at all this weekend?? I was hopin you were out side that way I could take you for a ride in the truck. Also before I forget, are you the kid that had the red s10 last year that I had to put in the freeze plug??
Nick

[Sparky2263]

I have to plug in a 23 inch tire to get 2900 rpm's at 70 mph. Here's the calculator;

http://www.csgnetwork.com/rearendgearcalc.html

My 4.10's had me about 2400 rpm's at 70 mph.

[Joe]

I have to plug in a 23 inch tire to get 2900 rpm's at 70 mph. Here's the calculator;

http://www.csgnetwork.com/rearendgearcalc.html

My 4.10's had me about 2400 rpm's at 70 mph.
I have a 25in tall tire with a 5 speed tranny.
Hope that helps

[1993blazerlt]

did you correct you speedo because larger gears will throw that off making it look like you are going slower than you are

[Joe]

did you correct you speedo because larger gears will throw that off making it look like you are going slower than you are

Yeah, with the programmer that i got with the wynjammer I corrected my speedo with the gear swap and the tire change, lol still sucks but ohh well thats the price you pay for speed I guess.
Nick

[Sparky2263]

.83 O/D with a 25" tire at 2900 rpm's is (drumroll please) 70 MPH!!!!

Tiny tire for a manual.

Us auto guys have a .7 O/D. BIG difference.

[XxInFaxX]

How come you park at the end of your driveway??? Also Did you see me come through you track at all this weekend?? I was hopin you were out side that way I could take you for a ride in the truck. Also before I forget, are you the kid that had the red s10 last year that I had to put in the freeze plug??
Nick

because i usually get home at like 5amish after a night of partying, so i park down there so my mom can get out with her durango. trust me, last time i didnt she sideswiped my black s10. yes, i am the one with the red s10 with the freezeplugs. i still have it actually. sittin at my dad's...needs some tranny repair, blew out reverse.

[Joe]

.83 O/D with a 25" tire at 2900 rpm's is (drumroll please) 70 MPH!!!!

Tiny tire for a manual.

Us auto guys have a .7 O/D. BIG difference.
my truck originally had the 235/55/16 or something, now I have 245/40 my tires are 1% smaller than my stock ones that came on the truck.

[biglouie_underpressure]

sounds like someone needs a t-56

[Maximus]

Before I saw your tire size I was like something really isn't adding up here.So you really don't like the gears.But just think of all that wonderful acceleration you have lol.At 2500rpm I am running right at 75mph.And according to that calculator I will get cut to around 67 mph at the same RPM.Not bad makes me wanna throw those 4.10's in even more now.

[xtreme canuck]

so have you ran your buddy with the s/ced 5.3 again ? maybe that will make it all worth it. have you picked up a big difference in the 1/4 ( estimated ) or do you lose too much traction ? good to know about the gears though i am thinking of doing the same but maybe i'll rethink ....i like highway cruizen
thanks for the info

[Joe]

so have you ran your buddy with the s/ced 5.3 again ? maybe that will make it all worth it. have you picked up a big difference in the 1/4 ( estimated ) or do you lose too much traction ? good to know about the gears though i am thinking of doing the same but maybe i'll rethink ....i like highway cruizen
thanks for the info

No i havent ran him since the gear swap, but he thinks that i deff got him now. I really dont like to gues 1/4 mile times but i would say roughly mid 14-5, 14-4 ish. But remember that is merly an assumption.
I drove the truck a little more tonight and the gears are deff growin on me. I really do love the acceleration. I may just go with a taller wider tire in the back, that should help it a little more for cruisin, but i am worried it will mess with the abs.
I noticed that I can cruise at 65mph comfortably. So I like them alot better. I would love to do a t-56 swap but I aint spendin another $3000 on performance. lol
Like I said the more I drive it the better I love them. Its just that it is a HUGE difference, more than what I was anticipating.
Nick

[LEADFOOT]

I have to plug in a 23 inch tire to get 2900 rpm's at 70 mph. Here's the calculator;

http://www.csgnetwork.com/rearendgearcalc.html

My 4.10's had me about 2400 rpm's at 70 mph.
That calculator is pretty nifty. I like that. Its pretty accurate too. With my stock 3.42's and 25" tires (I believe thats the correct tire height), at 70 mph I'm turning just under 2300 rpm and thats what it says. So if everything works out with the calculator if I put in 4.10's like I want to, at 70mph I would be turning 2700 rpm. Not that big of a jump in rpm IMO for my truck. If I put on 26" tires at 2700 rpm I'll be running about 73 mph. One last thing my speed at 4500 rpm with 4.10's and 25" tires would put me at about 117mph. Even with the wynjammer I don't think I would be pushing more than that in mph at the 1/4 mile. I know I won't be doing that on the highway. I don't know how the law is in other states but in florida if you are caught going over 100 mph they can take you to jail, you have to pay a fine and pay impound fees for how ever long you are in jail. So for me top speed isn't a factor unless I get to the 1/4 mile and run out of pedal, that would suck.

What kind of gearing do the high HP dragsters and fast cars running under 10 sec. in the 1/4 have? Is the transmission gear ratio different by that much?

[Sparky2263]

Leadfoot, they changed the law for us Floridians. Anything 30 mph or over posted speed can be charged as a felony. Scary or what? Seldom happens unless you got something else. Same thing for street racing. Felony now.

Top fuelers and Funny cars are limited to 3.20 only.

Pro-Stock and the rest of the seriously fast cars that run the big ass 33x15 run between 4.5's and 5.3's. But they've got a 33" diameter tire.

Got me curious now. I'll go get the rulebook and edit.

I plugged in a 4.5 gear turning 9500 rpm's to get 207 mph in a Pro-stock.

[tunerpike]

I want to install 3.73 in my 1995 4.3 ext. cab auto trans. I don't know if I need the 2 series or the 3 series. I either have 2.73 or 3.08. Can anyone help?

[Sparky2263]

3.08 and lower are 2 series gears.

3.23 and up are 3 series.

[tunerpike]

Did not know that. "If you don't learn something atleast once a day you pissed your day away." Thanks for the info.

[Sparky2263]

Actually, Pro Stock now runs a 16" bead lock wheel.

[lyonsfam1]

is there any problem putting either 3.42's or 3.73's in a rearend that already has a lsd? i have 3.08 with the lsd and i dont want to lose the lsd to fit a different gear

[Sparky2263]

With the 3.08's you have a "2" series carrier. You need to buy gears for that carrier rather than a "3" series carrier. More commonly known as "fat" gears.

[Mintsick]

is there any problem putting either 3.42's or 3.73's in a rearend that already has a lsd? i have 3.08 with the lsd and i dont want to lose the lsd to fit a different gear

It depends, if you have a 5spd truck post 1998, chances are you have an 8.5" rearend (all 2000+ 4.3 H.O. 5spd trucks come with an 8.5"). If this is your setup, you do not have to worry about what "series" rearend you have, an 8.5" 10 bolt carrier will accept gears all the way up to about 4.56.