Mr. Sandog

Okay guys, I'm in the home stretch here....the shop has 4.10's waiting for me, but I can still decide to just do the Eaton and leave the 3.73's in there. I'm still on the fence, and here's why.

Right now I have 100% traction - unless I hit water, make a turn, or try and turn them over (as in a brake stall, etc.). So this is what originally led me to believe that I could deal with 4.10's.

But now I'm thinking....the converter in the new 4L65E I am getting ready to install was made to stall 1800 RPM's behind a 3500 lb Corvette....so I bet it will stall 2100 to 2200 RPM's behind my 6000 lb Avalanche, as opposed to the 1600 RPM's I'm stalling at now. Coupled with a 3.0" pulley (I have the 3.4" right now), this will probably mean that any traction I now enjoy will be gone.

So now the 4.10's don't seem like such a great idea, given what I'll be sacrificing (a little mileage, more RPM's at cruising speed, less traction, etc.) over what little I'd be gaining.

Actually, I like the converter I have....no slipping whatsoever, which I'm sure is partially responsible for me getting 15 mpg around town in a 3-ton vehicle. Plus I chose my cam based on keeping the stock converter....if I had planned on a 2500 stall (Trailblazer, TT2600, or otherwise), I'd have gone with a bigger bump stick. So stalling at whatever the stock stall speed with the converter that comes with this 65E will be fine with me.

Finally, remember this is not going to be a drag truck, this will be my daily driver, albeit one that I wouldn't mind surprising a few people with. Also remember that this is really only a 10% change, though that can make a difference. Any final words of input given my needs and concerns would be appreciated.

Leroy_454

If i were you i would keep the extra coin and stay with the 3.73's. If you had the 4L80E trans or were going to swap, i would definitely say 4.10s. I think as long as you stick with a 4L60/4L65E and have the radix, 3.73 will be the best all around gear.

Mr. Sandog

I appreciate your response, but would you mind saying why you recommend this strategy? I'd like to know your thinking behind it - thanks.

moregrip

iTrader: (8)

4.10's

Mr. Sandog

Why??

moregrip

iTrader: (8)

haven't we talked enough about this?

Mr. Sandog

You've certainly said "4.10's" enough times, but I'm not sure I've ever heard your reasoning behind it...especially given my setup, goals, and constraints.

Besides, I think it would probably help a few other people to hear where you're coming from.

moregrip

iTrader: (8)

ok bro, one more time, as if we haven't discussed this many times over the phone.

I say 4.10's because, I used to have 3.73's and now have 4.10's, we both have 32" tall tires and closely weighted vehicles, although different trannys. What have I learned? In a very broad and general stroke of the English language, my truck feels more athletic with the 4.10's, it stays at/in/and near the meat of the powerband more often than with the 3.73's. Off the line response is better, in all cases!
According to your above criteria, the 4.10's make more sense, IMO, especially since this isn't a "Drag Truck". How so? well, since your not going to be mashing the pedal at every light, the 4.10's will get your mass moving quicker and with more ease, effortless acceleration, so to speak. As I've said many, many times, IMO, as long as you can live with the 250-300 additional highway cruising rpm's this is a good move. If total strength of parts was your primary concern, you'd be swapping out the 10bolt anyway, so since this is your daily driver in the guise of a sleeper, partial throttle off the line acceleration will be improved with the 4.10's. If you had a "Drag Truck" 3.73's might be a better choice, might be, as you would be mashing the pedal all over the place. I say might, because if you could get 4.10's to hook, IMO, you would and should go for the most gear you can get away with that would not slow down your trap speed.
All in all, 4.10's feel better, to me.
I'm sure I have more thoughts and opinions but I'm tired of hunting and pecking, and we have discussed this on the phone several times.

Everyone, this is my opinion, take it for what its worth

12sec.5.3

iTrader: (1)

Very well put and understandable Grippy. If you can't decide, find a happy middle. 3.90 I like mine.

koochingchang

just got 4.10'd and i love it! coming from 3.42's and its a great improvement.