Hey Everyone,

I'm looking for a little insight before I purchase my diff package for my 05 ecsb. Currently the truck has 3.23 gears which are great for the highway, but leave some to be desired around town or on hills especially when I'm currently working with a 4.8. I'm going to repace the 4.8 with a ls6 stroked to 383 with some other work. Besides that I'm looking for upgrading my rear with a tru-trac and new gears. I am leaning towards 3.73's so I can keep my highway economy (most roads around here as soon as I get out of town are 50mph plus), and fear that 4.10's would be too much. I'm not looking to race the truck all the time (maybe 20% if that), just want good all around gears for performance and economy, and am thinking the torque of the motor along with a stall will make up for the 4.10 difference. Also the tires I'm running are a little over 31" tall I believe (285/50 20). I don't mean for this to be a 3.73 vs 4.10 debate, just looking for some input on which may work best for what I'm looking to get out of it.

 

I lean to the more conservative side; I like 3.73.

I prefer to let the engine make torque instead of just spinning the engine higher.

 

what converter are you going to run? 3000-3200? i say 3:90s with that tall tire and it being a DD. im running 4:10s in my CC on a 31ish tire (265/70/17) i turn 2350 at 75 and i still get 19-20mpg on the highway and 14.5-15 in city depending how much i play i like even though i have a 6.2, 228/236 112+2 cam, 3600 converter, 4:10s i still get descent gas mileage for what it is. if i had to do it over from 3:42s to 4:30s imo. you're lighter so i say meet in the middle of your 3:73/4:10 debate. 3:90s is my vote, White1 is running a 4.8 CCSB with 4:10s now, he kinda wishes he would have went 3:90s

 

im going 4.10s with a 305 40r22 but mine is ccsb. 3.90s would be ok for u i think

 

3.90s are available if you can't decide between 3.73s and 4.10 I had 4.10s in my last truck with that same setup... 4.8 60e and 4.10 with same tire setup and it was not bad at all. still had excellent highway driveability. but if your worried maybe look into a 3.90... if I could find 3.90s for a 9.5" rear that's what id be going with.

 

I like the 4.10s like them more the more I drive with them too. I do mostly highway driving, and if I had it to o over, Id go 3.90, only because of the amount of time Im between 70-80.

If youre split between 3.73 and 4.10, 3.90 is right there.