I have aftermarket tires - 285/55/R20 Dick Cepek Fun Country on the factory Sport wheels. No issues whatsoever. They're a bit noisier than the factory tire, but nowhere near as loud as you'd expect. I am extremely happy with them. I just wish I had thought of getting fender flares before I ordered them, so I could have gotten the 305/55/R20s and spacers. I just didn't want the tread sticking out past the fender.

 

Did you get the new tread or the old FCIIs? I had the FCIIs on my 3rd gen for eight years. Wore like iron, great in all but really sloppy mud, but noisy was an understatement. The new tread design is supposed to quite them down a good bit...

 

I had to take my 3rd Gen to 4 Wheel Parts to properly balance when I went to 35" tires, they were closest place could road force balance. Also, they were the closest place could fit my truck on the alignment rack. I was too wide for all the normal tire shops...

 

Thanks for the info. I didnt have time today to take it th the discount tire that i bought my rims and tires from, but at least the manager is being awesome about the problem. He even road with me to see just how bad it was shaking. He offered me another set of rims to see if it does the same thing but i really had my eye on these for 8 months before i bought them and i want to do everything possible to try and keep them.

 

I really wish i had kept my 2003 1500 it had no issue what so ever with big tires and wheels. No vibration, no anything. The other thing i have though about was the bilistein level struts in the front set at 2.5 but the vibration and resonation feels like its coming from the rear and its shaking left and right not really bouncing. The tires where at 46 psi so i lowered it to 40 psi just to see if that helped and it sofened the shake but it was definitely still there.

 

Was the shaking bad on your 3rd gen and did it completely disappear after or was it there a little still. See my truck also has huge weights on the frame for resonation drone im guessing, i dont know if it might make it worst or what. I have thought about everything i can think of.

 

I had a vibration in the front, not terrible but clearly noticeable. I attributed it to having fairly aggressive tread 35" tires. Funny thing is it would rear it's ugly head at about 65 mph on the highway and go away at about 75. I had the rears and fronts swapped at normal rotation time which for me is about 6000 miles, made no difference.

After about a year of just accepting it, I had all my tires road balanced and an alignment done and it went away for good.

I don't think it's the coil 4th Gen, I've installed lifts up to 6" with 37" tires and nobody complained to me about excessive vibrations...

 

These are the what's-old-is-new-again "regular" FCs, not the IIs.

Back in the 80's I always wanted to get the original FCs but couldn't afford them, then marriage and kids happened and I was off trucks for a while. So I am doubly pleased that I have them now - the sentimentality and the straight up performance (which is undoubtedly way better than the originals).

 

With the ones I have its so unbearable and it Resonates worst, but mine is definitely in the rear of the truck. I just dont understand i have had all kinds of big rims and tires with no problem ever. Im gonna talk to the Discount Tire Manager today about road balancing if not $ wheel parts is 5 mins from my work.

 

I do see one possible variable. I've never installed or helped install a lift on a truck with large wheels.

Most guys I installed or help install lifts for are word of mouth, hunting club guys who are generally older and lift for functionality and off road performance rather than the coolness factor. Functionality is maximized by as much sidewall as you can get. So these guys either bought trucks with smaller wheels, have already swapped out or are doing so when buying the larger tires right after lifting the truck.

Not saying with certainty it's your wheels, just it's a variable I noticed in your signature different from installs I have done...