I get about 14-16 with 33s and 4.10s, hand calculated. I can pull almost 18 on the highway if I set the cruise at 60mph...

 

Thats pretty good. Hows the power? Think I will probably make the switch when I get my new tires.

 

Do you believe it increased since the gear change?

 

sorry but I have a gryphon cs too, I was soo happy when I got it because it says my mpgs are 16-18, which sounded awesome because I was getting 9mpg's before. I always check it manually when I fill up, ended up actually only getting 12.5avg. Better than 9 but not as good as it was saying. You should check it manually to compare, just a thought. BTW this is all with a 4.6l, 3.55 gears and 35in. Toyo's.:o

 

Im looking to do the same, I have an 04 with a 4.6L with stock 3.55.
I just put a set of 33s on it and its very sluggish.. I was gonna go the 4.10 route to try to get the truck back to normal, but from what ive read and researched, ill be running around 2700 rpms @65, were right now with 33s @70 im only running 2000 rpms.. Am I right in saying this??? I mean they say bigger tires and gear changes help it get back to stock, thats pretty far away from stock 700 rpms.. Maybe I got this all wrong, I really dont know to much about the subject, I just now as it sits now my truck is slow, I want to make it quicker with the larger tires I just put on.. Please feel free to weigh in...

 

Power is good. Run a 0-60 in under 9 seconds (around 8.8) with 33s and a toolbox. Wet weight is about 6600lbs right now.

With 33s I'm at 1950rpms at 65mph, most calculators online are at a 1:1 ratio and don't include overdrive.

 

Well that comforting, didnt realize they didnt take overdrive into account..

 

You need a programmer to correct your speedo and odo - they are no longer accurate with the larger tires.

I would definitely go to 4.10's, and if you have 4wd you have to do BOTH axles.

 

Yep. She was a screamer on the stock 245/70R17 tires, but if you're never running smaller than 33s the 4.10s are great

 

I knew I needed a programmer to adjust the speedo, but I had know clue it will affect the odometer, seriously??? Ill be honest I don't know that much about all this, never messed with the gear ratio in a vehicle before.. I mean do I need the programmer as soon as I do the gears, cause the just the gears and the install is taking all my money.. I guess I should ask also if the gear change will affect transmission shift points, which the for mention programmer would be needed..

 

The shift points will be the same, unless you just want to change them. The speedo/odometer will be off without the programmer, so you will be recording mileage quicker and the speedo will read faster than you are truly going. The gear change is usually around $800 with parts included, and a programmer is ~$400, so you'll have at least $1,200 into this swap.

 

Thanks for the info, I priced out a set of Yukons and install kit for under $350 and found a shop who said around $400 for install, I knew the speedo would be off and just planned on riding it like that for a while, but didn't realize about the odometer being off, which is something I cant just let ride for a while... Just keeps adding up, damn.. may have to hold off on this for a while..

 

If you don't tow much, I wouldn't worry about it. If you do tow, then I would probably go with 4.30, or 4.56 if you go up to a 35" tire...

I have 3.55 with 35s and no problems related to tire size. I am tuned with a SCT XCal2 and it works fine. Speedo / Odo are accurate, not a dragster by any means, but techically I am running "highway gears", meaning the gearing allows the engine to run at lower RPM at highway speed due to the effective overall ratio with the 35" rubber. I get decent (not great mileage on road trips in the high teens, however in town / mixed driving and towing stinks.

YES I have had, very recently in fact transmission problems, but not related to the tires. I had a bad oil pump seal and vent line leaks that I fixed, including replacing the pump gasket and O ring seal. It's working great now. VERY little wear material in the pan and magnet.

 

I would have to imagine your truck is a pig regarding acceleration. Hell, I've got the 3.55LS on mine with the stock 32" tires and it's nothing to write home about, and a programmer won't help that much. 35's would make it unbearable, especially while towing a trailer. I think 4.10's are acceptable for stock to 33's, and 4.30's (if 2WD) or 4.56's are needed for 35's just to keep performance respectable.

 

I'm not winning many drag races for sure, but then again, towing is reasonable, off the line is fair, not great. Yes I know I need gears, but it isn't quite as bad as you make it out to be...

It's quicker by a large margine off the line, and overall than my friend's relatively stock '00 4.6L XLT 2wd...