mrb04

Vehicle Is A 2005 Yukon With A 5.3 Bored To A 5.7 With A Sts Turbo. Truck Is In The Transmission Shop Right Now ( Truck Has 600 Miles On It Most Of Which Was Dyno Time And Transmission Is Gone ) It Has 315/35/24 32.68 Tall On It And I Believe 3.42 Gears. The Transmission Shop Is Saying That It Would Benifit Both The Truck And The Transmission Greatly If We Were To Put Say 4.10 In What Do You Guys Think. This Truck Is 90% In Town Driving And The Gas Millege Already Sucks Its Getting About 9. Truck Is Putting Down 480 Wrhp And 550 Rwtq.

quicksilverado

iTrader: (8)

Keep the 3.42s you don't need the 4.10s with the turbo.

mrb04

I understand what you are saying but it takes alot to get this thing moving

Mr. Sandog

Nice numbers.

You can get gears, that's for sure....with 3.42's the off-idle torque can't be that good. Do you have a converter? If not, you might want to consider an aftermarket converter before you get gears. Get a large (11"-12") tight 3000 or 3200 stall and if you still don't like it, get the gears. Reason for this logic is, you will probably want to get a converter anyway, so get it and see how that is first.

quicksilverado

iTrader: (8)

If you do as much driving in the city as you say, then 4.10s will help with the mileage. When I drive mostly in stop and go traffic I normally get 15-16 mpg. The truck weighs about 5300 lbs with work tools and me in it. I have 3.42s also. I have a 4l80e which makes the truck really hard to get going with the stock tq converter. My rwhp #s are very close to your also. Try going easy on the pedal and see if that helps any.

mrb04

Yes It Does Have A Tci 3000 Stall And I Don't Really Care To Much About Millege But Don't Want To Hurt It Any More. More Important Is It Taking Off Hard

quicksilverado

iTrader: (8)

What size is your turbo?

mrb04

Gt-67

sleek silverado

iTrader: (4)

I think 4:10's would benefit you, considering Yukons weigh a lot.

mrb04

Just Looked Up Vin And Factory They Are 3.73. By My Calculations The Truck Would Really Run About 50 Rpms Over Factory On The Highway But About 200 Rpms More Then Now.