I just ordered a 4" rancho suspension lift and now i need a new set of tires. Im not sure what size as i have a 3" body lift already with just stock size tires. I need to keep in mind MPG, i dont want that to drop dramatically. I just dont want the tires to look to small for the truck but just right.

 

You could get 25's in tere with no problems at all.And I think your MPG wouldn't drop drasticly especially if you dont have the 3.55's.

 

I think that the 35/12.5 tire is your best bet and safest way to go. You will now have a total of 7" of lift in front and 5" in the rear and if you go 33's they will look too small on it IMO. Now you could try 37's and that would look awesome, but you would probably want to regear your truck for a better ratio, so that would be even more money and 37's might be tough on your suspension down the road? I really think 35's in a agressive tread like a Toyo mud or a Micky Thompson MTZ would be the meanest and safest way to do your truck and if you do it please post some picks.

 

Anything smaller than 35's would look too small with that much lift, anything much larger starts to put a real strain on IFS components. So I'd say 35's would be ideal.
Your gonna run into power issues with big meats like that with a 4.7, as I could really feel a lag with my Hemi after the Ranch lift and 35's. You should think about 4.56 gears as your next mod.

By the way, let me know if you have any trouble with the Rancho kit working with the body lift. I've heard conflicting reports on the compatibility. Rancho's policy is they strongly don't recommend any other lift method with their kit, but won't say that it won't work.
Since I picked up a Grand Cherokee for my daily driver, I've been thinking of going more aggressive with my truck...

 

his truck is a 2002. I dont think he has an IFS. I would run 37's with that much lift all day long

 

I thought ALL the 3rd gen 1500's were IFS. I know all the lift kits for Dodge 1500 T-Bar trucks list good on 02-05, so that right there tells me it's IFS.
If I'm wrong and he's SRA, then by all means, 37's. But then he's really gonna need gears or he won't be able to get out of his own way...

 

i thought only the 06-08 1500's had IFS. I could be wrong, not really sure

 

06+ have IFS and coil overs. 02-05 have IFS and torsion bars. Trust me, I have an 04 and it's IFS, wish it wasn't, but it is...

 

didnt know that

 

What size rims are you going to be using for the new tires? Because if they are 20's the tires aren't going to be cheap! Are you going mud or all-terrrain?