Gears!!!

[Z-56 Hoe]

4.56 gears is what you need. 6.0L or not. Those gears will put you closer to back to stock.

 

[Bonestock]

Bingo! I just added 285 Nittos.. I noticed it down shifts a LOT more now and hates even the smallest inclines. I will never put bigger than a 285 on this truck because I DD it and I just like the way they look better. If stock is 3.73 with the 265 and 4.56 with the 35's then I should be looking at doing 4.10 or 4.11 with the 285's?

 

[ezdaar]

Have your up/down shift points changed via tune. duh..

There is more to it then just slapping on some big ass tires and changing gears.

 

[Bonestock]

I know that but I figured regearing would get the RPM's back where they needed to be and that would be more beneficial than changing the shift points. I guess what Im trying to say is with the 285s the spinning weigh is greater and they also have a greater diameter and the already under powered 5.3 lost some much needed mechanical advantage. That said I if the shift point is changed to keep it from downshifting that doesn't increase the power of the engine which is what is needed to maintain speed going up hills. Correct?

 

[01Konvict]

Yes in a weird question, but either raised shift points will help maintain speeds or new gears to keep engine speed lower.

 

[Bonestock]

Can you help me understand how raising my shift points will stop my the downshift from OD when I'm running 65 mph and come to a hill. I guess I should mention I want it to be able to pull the hill with out losing much speed either. So if it doesn't downshift I'll continue to lose speed?

 

[01Konvict]

Raising shift points wont help you cruising on flat ground at 65mph then start up a hill trying to stay in OD. It just helps give you more RPM longer in a gear to increase speed faster. If it's that noticeable with the 285s then do front and rear gears. Everyone else I know seems to tolerate the heavier tire for size and just mashes the pedal more. I'm assuming those tires are close to if not more than 70lbs each and stock tires weigh 50lbs. That is what is killing you on gears and maintaining speed. The gear helps turn them over faster which is easier on the engine due to the added weight. Unfortunately you will either add more HP to the engine or do gears to keep the pep it had with lighter tires.

 

[hoe]

I agree with 01Konvict & Ezdaar! I run a ** 6.0, 4l80 trans, 2wd, 3300 stall, 4.56 gears, 35x12.5x20 inch tires, Professional PCMforless custom tune by Alvin. Its PERFECT.

What we are talking about is shift extension before shifts. Hold it longer more power, but its a difference with leverage and torque from the gears. You need both. As a matter I ran 4.88 gears in this truck before with a 32" tire. Now with the 4.56s, 4l80 and 35s things are perfect. I would love to try 4.88 with these tires now, but its already plenty. The tune is even more special, cause not only shift extension can be longer, but kick-downs can be faster at earlier speeds. Trust me, my shit flies.

Get gears that stay in the sweet spot for your tires. If you travel highway alot with 35s then get 4.30s. If its in the city or 1/8th mile 4.88s or 5.13s would be narly fast with supporting mods. If its a mix of both get 4.56s. If your not NA and superchargerd keep 3.73s. If you have a bad ass twin turbo setup get some 3.42s. You WILL hate one and LOVE the other!

 

[jerryjoe28]

4.56s with 35s on mine and it will move even at highway speeds... now i have no idea what my mpgs are but it cant be any worse than the stock 3.45s with the 35s lol

 

[hoe]

Lower the gears the more decreased top end you will have. Actually 3.73s have more top end pull than 4.56s. But I agree 4.56s pulling good on the highway is relative. They do still pull hard. Another truck or smaller engine that has some 3.42s with some boost of any sort, will walk it on the highway top end.