The week of February 7th my G80 is getting swapped our for an Eaton posi. If I'm going to change gears, this is the time.

I thought that staying with 3.73's was the way to go, but after talking with a few more guys, once again, I'm not sure.

Here are my specs:
- 5.3L motor
- 205/212 Cam
- Radix SC
- 4L60E (soon to be 4L65E)
- Stock Torque Converter
- 305/50-20's (31.6" high)

Right now, at 70 mph I am going exactly 2,000 RPM's. At 80 mph I am going 2,200 RPM's.

I'd like some more power down low (who wouldn't?), but want to know the downsides, if any, of swapping to 4.10's.

 

You can expect about a 10% increase in rpm's at any point over the 3.73. So at 70mph, you should be at 2200rpm's.

I know how you feel about this, but with your setup, I'd rather have a 2600 stall and keep the 3.73's.

 

I like the sound of that setup, especially if you drive the highway a lot. Something else to consider is whether you like the way the truck will sound at the higher rpm for highway driving.

 

I would say stay with the 3:73 and get a TQ converter. I think with the radix you are making plenty of power down low. I actually think adding the 4:10 will make a little to much power down low. I say stick with the ones you got.

 

In OD it would only be about 7% increase in rpm.
I would also vote for a stall. I can say that it will be the first non-driveway mod I will do. If you had 3.42's I would say the gear is a good idea, but from 3.73 to 4.10 could almost be accomplished with a tire size change.

 

what's wrong with the g80?
go 4.10's all the way, you won't regret it

 

3.73's and 3000 stall with Eaton is the ideal combo. anything more than that you will spin TOO much and it is not all that fun

 

maybe you should tell everyone you want to keep your stock stall.

 

btw, I say go 4.10's, I've had both, and like the 4.10's better.

 

If you've ever seen James B.'s pictures of his G80 you'd know "what's wrong with the G80." You'd know why a lot of people say the 'G' stands for 'Grenade'.

Seriously, I've added well over a hundred horsepower to a vehicle that weighs three tons (plus) with me in it, with a 8.6", 10-bold rear end. That's a disaster waiting to happen. And I've heard that many times when the G80 goes, it takes the tranny with it. Not something I desire to do. I'd rather pay a few bucks to swap out the G80 now, than have to replace a rear end, gears, and a tranny later.

Thanks guys for all of your input. I wish I could drive someone's vehicle who has a Yank TT2600. If I was going to get a converter, I think that is pretty much the only one I would consider.