[DBA]

So all you guys running the 315/75/17... are you useing the stock keys cranked down..., that came with the 245 size tires?(if so how does it ride?) or are you running a 2inch lifted ones & cranking em down..?(if so how does it ride?)

will you get a better ride out of the 2inch keys, than the stock keys...

I wanna tow my 37' fifth wheel toy box... would running 315's be to much... on the tranny? would I have to regear? or should i go with 295's or 305's?

what do you guys think...

 

[sledog]

The only time you really need to purchase different keys (green keys) is when you don't achieve enough height from cranking your factory keys all the way up.

As far as your towing situation, I don't think it would be a problem. Last summer I went from Phoenix to Alberta pulling a 24' bumper pull cargo trailler loaded up with a 70 charger and almost another full car in parts in and had no problems.

 

[DBA]

thank you for the info.... now, did you have to put keys on your trucks...where do you get green keys

The only time you really need to purchase different keys (green keys) is when you don't achieve enough height from cranking your factory keys all the way up.

As far as your towing situation, I don't think it would be a problem. Last summer I went from Phoenix to Alberta pulling a 24' bumper pull cargo trailler loaded up with a 70 charger and almost another full car in parts in and had no problems.

 

[WanaDmxsub]

The problem with towing in Cali with 315/70/17's is that at 55mph the truck will never shift into high gear with the T/H activated. At 60 it will just make it. You may have to turn-off T/H and let the truck shift to high, then turn T/H on again...not that it does anything once it is in high gear. The other thing you will notice is that it may down shift more with the 315's, since you will be running a lower rpm and stuck at 60mph in Cali. Once out of Cali you can ignore most of this.
I have 315's and pull a 7k lb TT. No real problems here.

 

[LB7Fassler]

Would a person be better off installing a Cognito leveling kit to fit 35 inch tires? The 315/70/17's are what 34.5 inches tall, most 35's are about that too except the fact that they're wider. Because of the lack of 315's in that size from tire manufacturers I'd be better off going with a simple 35 inch tire, although MT MTZ's are made in the 315 size...

 

[sledog]

thank you for the info.... now, did you have to put keys on your trucks...where do you get green keys

I'm not using green keys in my truck. Green keys are a waste of money if your not needing more front suspension travel than what is there on the factory keys.

Green keys are the keys that are in the 1/2 ton pickups. They can be purchased at your local stealership, online auctions, or some of the vendors here.

 

[sledog]

Would a person be better off installing a Cognito leveling kit to fit 35 inch tires? The 315/70/17's are what 34.5 inches tall, most 35's are about that too except the fact that they're wider. Because of the lack of 315's in that size from tire manufacturers I'd be better off going with a simple 35 inch tire, although MT MTZ's are made in the 315 size...

There's a few DP members that are running the Cognito leveling kit. It does help with the geometrics of the front suspension and steering. I have always just did the torsion crank with all of my trucks since the IFS system came out and have been satisfied with the results. This is my first truck that I have used H2's and 315's and am finding that there is a bit more to it than just running 285's (ebrake cable tie back, longer lower shock mounts). I think I will be getting the idler and pitman arm braces to help beef up the steering.

I never looked into 35" tires as long as I can get 315 take offs for about half the price of most new tires. I am limited to one make of tire but its the tire I would be buying if I had to purchase new anyhow

 

[DBA]

There's a few DP members that are running the Cognito leveling kit. It does help with the geometrics of the front suspension and steering. I have always just did the torsion crank with all of my trucks since the IFS system came out and have been satisfied with the results. This is my first truck that I have used H2's and 315's and am finding that there is a bit more to it than just running 285's (ebrake cable tie back, longer lower shock mounts). I think I will be getting the idler and pitman arm braces to help beef up the steering.

I never looked into 35" tires as long as I can get 315 take offs for about half the price of most new tires. I am limited to one make of tire but its the tire I would be buying if I had to purchase new anyhow

your talking about the Cognito upper arm lift... ? anyone ever did the upper arm & a set of keys?
lol
would it work... what could you fit...

I like the look of a stuffed fender.... 315's look good guys..

now if it bought a programmer to adjust the speedo... would i still have to put it in & out of tow haul... at 55 or 60?

 

[sledog]

your talking about the Cognito upper arm lift... ? anyone ever did the upper arm & a set of keys?
lol
would it work... what could you fit...

I like the look of a stuffed fender.... 315's look good guys..

now if it bought a programmer to adjust the speedo... would i still have to put it in & out of tow haul... at 55 or 60?

I'm thinking that your front CV drive axles are going to be on some serious angles if you go with the Cognito upper arm lift, green keys and cranked torsions. You would also have to get longer front shocks and probably a 1 1/2 - 2" block in the rear unless you like the look of your truck being higher in the front. There may/will be premature wear going on the front end with that set up.

When you engage the tow/haul button it basically raises your shift points and gives you engine braking under deceleration. With 315's at 60mph my truck is reving about 1550rpm almost target for gm advertised max torque.