I was wondering if it's safe to run 37's without re-gearing with a 6'' suspension and 3'' body lift? Also how slow will the truck be when taking off and how much gas mileage would I get?

 

your truck will be slow lol

 

You can do it but your transmission and gas tank will hate you. It will be VERY slow accelerating and your city gas mileage will be terrible, like 9mpg. You really need 4.56s or 4.88s. What engine and what stock gear ratio do you have?

 

buy your 37's then save up for a gear swap or take the money your going to spend on 37's and re gear it before hand then save up to buy the 37's.

but like other post say its going to kill you mileage and possibly your tranny if its not in good shape to begin with.

 

You can do it, but its just going to cause trouble and be cheaper to buy gears instead of a tranny. Especially if you have stock 3.55s, I would not suggest doing that at all. If you have 3.73s, thats not as bad, but still not great. Your gas mileage will probably be around 8 mpg, your tranny won't last very long, and the truck will be slow.

 

Well being that we have no info on your truck like year and engine it's hard to say. That being said I have been running 37's with the stock 3.73's for 25k miles and average 13 mpg. I take it easy, yes it's slow but it's a truck so I don't really care. I will be re gearing soon. But, take it easy and you should be fine. One thing that helped a lot with taking it easier on my transmission was upping the shift points by a couple hundred rpm with my tuner. By doing so it cut down the transmission trying to find the right gear and shifting to often.

 

Yes and no. Its not terrible just in my experience when it came to hills is when everything was under pressure and the truck couldn't find the right gear. And id look at 4.56 since 4.88 are too much for 37s