Got my new wheels and tires on Saturday and love them. The only disappointment I had was that I was told by several forum members that when I went to the 35's with my 4:88's and 6-speed, that the rmps would drop significantly at 70 plus mph. I have no drop whatsoever. I am running at the very same rpm I was with stock M/T's. Don't know how this worked out for you guys, but mine did not change at all.

 

Did you adjust your speedo for the 35s? If not, I think that's your variable here...

If you are clocking the same RPM on the engine, now with 3" bigger tires (causing you to travel further per rotation of those tires), you are travelling > 70mph.

If you adjust the speedo, I think you'll see the RPM be lower at actual 70mph, whereas now you are probably at like 75mph+ to reach same RPM levels. So, RPMs DID drop at a true 70mph, just not 70mph on your speedo b/c its wrong...

EDIT: This is working on the assumption that you had the 4.88s with 32" tires before, and now 4.88 with 35" afterwards (b/c you just said you got new tires - not new tires AND new gears). RPM would most definitely drop given this scenario (scientifically has to).

If you changed the wheels and tires AND the gears (from 4.10 to 4.88) at the same time, then what those are saying below is accurate. You will be back near stock performance.

 

If I am thinking right, everything should be close to stock because of the increase in gear ratio. If you jumped from 4.10 to 4.88 with stock tires your RPMs would be higher, however, adding the larger diameter tire will spin fewer times than the stock tire resulting in close to stock RPM levels.

 

4.88 gives the closest to stock performance with 35s. its not exact but it is close to 32s and 4.10s. The 37s and 5.13s are almost exactly the same as 32s and 4.10s.

Your RPM should drop a tad, but not much.