3.08 to 3.42

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Jerryred94silvy

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What year is your truck? I seem to think that 88-94 TBIs had numerically lower gears vs. the later Vortecs? I don't know if it was because the TBIs had good low-end torque? My nephew's '90 C1500 F44 ECSB 350 had something like 2.73s. He did a LQ4/TH400 dragster swap and got regeared to 4.10. My brother's C1500 RCSB has 3.08 also. I don't know what my Dad's 89 1500 RCSB has, but probably something along those lines.

Didn't the later 1500 Vortecs have 3.42/3.73s mostly? Or maybe it was as the ECSB became more popular over the RCSB? Heavier truck requires numerically higher gears?

Mine’s a ‘94 model.

Am I better off buying a master rebuild kit, and then diff and gears separately? Or is there a master kit that would come with all of it together? I saw Jegs had one, but it wasn’t a Torsen style diff. Just looking for recommendations and experience.
 

Nickpisp

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Mine’s a ‘94 model.

Am I better off buying a master rebuild kit, and then diff and gears separately? Or is there a master kit that would come with all of it together? I saw Jegs had one, but it wasn’t a Torsen style diff. Just looking for recommendations and experience.

I’ve always bought all three separately.
 

1ton-o-fun

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10 years after I bought my '98, I swapped the 3.42's/Gov-lock to a set of 3.73's with an Eaton LSD.
275/60-15's.
Should of done that the day after I bought the truck.
Sure woke it up, but it did get a bit thirstier.
That mpg hit could of (well...more than likely. Probably!) been due the increased yippee-yahoo factor. It was like a different truck. Way too much fun to hammer down on the loud pedal.
If I'd lightened up on the right foot around town, it would have probably made better mileage due to not having to be pushed as hard to keep up with traffic.
But then, I've never really had a big concern over mpg's. Smiles per mile has always been the priority.

Exactly my problem in the Crown Vic world. I went from a civilian 215 hp, single exhaust, & 2.73 gears, to a Police Interceptor 250 hp, dual exhaust and 3.27 trac-loc. Sounds small, but WAAAAAY more fun. I don't have sense enough to stay off the gas.:Big Laugh:

Too bad Texas is so far away from Louisville Kentucky... both my half ton parts vehicles have 3.42's in them and won't be used in my 1 ton...
 

sewlow

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I had a couple TBI trucks, one I think had 3.08s, but with a 406 had NO problem pulling those gears, and then had a 92 Blazer that had 3.42s, that had 32s on it and was a bit of a dog, but it had 200k on it, so was easy on it. I had a 98 Tahoe that had 3.42s and 4wd, that had some pull to it, but nothing like the 98 that I have now that is 2wd with the same gears, that pulls great, but run out of MPH cause it shuts off at 100 lol.

It is possible to eliminate the speed governer.
 

redfishsc

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I went from 3.42 to 4.10 in my Suburban. No regrets.

Most of my driving is around town.

On the highway at 70mph my 4th gear engine RPM is a fuzz over 2000 which is perfectly fine.

I also tow a fairly heavy pop-up camper a few times a year, and the 4.10s really help with that
 

Supercharged111

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I always get a kick out of folks who say a small change in gearing isn't worth it. 3.08 to 3.42 is not insignificant. The right gear is the right gear regardless of how significant the change is. I've done big and small gear changes in my time. Most recently I went from a 3.73 in my Camaro to a borrowed 3.42 and it completely transformed the car.
 

b454rat

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Agreed!!! I had a 79 Malibu that was a factory 4-speed, had 3.08s in it. I swapped in a nice 454, didn't change anything else. I didn't get a chance to run it long with the 3.08s as I chipped some teeth off the ring gear. But it was a great all around gear. The 454 had more than enough to start off in 1st, even on a slight incline. But since I didn't plan on keeping the stock 7.5 rear, figured it would be a better selling point with more gear than the 3.08s. Found a cheap set of 3.42s to put in it. I hated it. It would scream on the highway, and didn't pull any harder than with the 3.08s. Starting in 1st was slightly better, but bout it. I sold the car like an idiot...but I like the 3.42s in my tahoe. Cruise at 70 the tach-o-meter says 2k, and will still pull hills no problems. Eventually will put in a 4L80, so cruise R's will be lil higher....
 

Erik the Awful

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Higher gear ratios are a crutch for poor torque. Big blocks work well with highway gears. Then again, all my big block experience is in big block Cadillacs.

Alternatively you can change your tire size. I have a set of dinky tires I put on my Mustang when I autocross it. They drop the car almost an inch and put me right in my power band. It looks a little goofy, but makes a huge difference in performance.
 
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