I have a buddy who has 4.10's in his hemi and I told him to switch to 3.73 for better speed and mpg. He's on stock tires, just got a superchip and is going to put on a throttle body spacer. He's worried about losing torque but doesn't tow anything. Should he do it?

 

i wouldnt . nor would i put a throttle body spacer on. they are worthless. it will be alot slower off the line with higher gears

 

Not enough difference between 4.10 and 3.73 to spend the money to change them. Mine has 3.92 stock.

 

EVERYBODY I know who goes to the track with their truck installs 4.56 or 4.88 gears for launch. YOU would be the first guy in my over 25 years around trucks and sports cars who has recommended going the other way. True, top end will increase by about 4 or 5 mph as it will redline just a tad later at WOT, but overall, going from 4.10s to 3.73s will decrease his performance and put more wear on his transmission.
He will also get WORSE gas mileage in town...

 

Bad idea. not worth the time and effort and expense.

You need to look around a bit and check out the FAQ section. it may answer all of your questions or concerns. HERE

 

agreed bad idea throw the tb spacer away and leave the 4.10s alone.....

 

Oh yeah I missed that, throttle body spacer has been dyno proven to LOSE HP on modern TB engines!!!

 

My goodness, one post and out? Not very good advice to go that direction on gears.

 

Do the gears! I'll send you my 3.73's and you send me his 4.10's. I won't charge you a thing, and I'll even pay for the shipping. I think you're onto something good. I'll even throw in my slightly used throttle body spacer so you can gang the two of them up together.

 

There ya go OP, the folks here always looking to help a brother out!!