LAK3RS

Also, do any of yall happen to know what the difference in 75w90 and 75w140 Royal Purple Synthetic Gear Oils are? Which one do I need.....I know it may seem like a stupid question, but I just don't know..LoL

Quick S

So what makes the 4.10s, not so good for the street as well (besides burning up more fuel[8D])?? I'm also an AUTO, and was looking at either 3.9s or 4.10s, as a matter of fact, I had talk to a few shops about an install, and they asked me about the driving habits of the car, I basicly told them daily and the occasional track, none of them told me it wouldn't be good for the street, and also talked to a guy at a car show with an 05' GT AUTO, with 4.10s, and had nothing but good things to say about it. So just curious if you guys have more input on this before I go buy some gears myself.
THANKS [sm=smiley20.gif]

06GT4RAD

As for the gear lube i prefer Redline over the RP and 75w140 is the one you want.

Richard

mustangman02232

take his opinion over anyone elses, those who have them, love them, people just think its to much

4.30s on 5 speeds
4.10s on autos

LAK3RS

Well....As of right now I just have the SLP's and CAI w/Tune. Though I do plan on doing all the basic boltons(LT's, Xpipe, H2o Pump, Pulleys etc., and maybe Nitrous in the future. So I guess I'm just trying to look ahead at what I might do.....So what Gears exactly should I go with then....3.73's or 4.10's....????..and Why?

jmk3

I'm about to do the same gear change. I would recomend getting the ford racing master install kit for this reason, the pinion bearing must be pulled off by the cage because there is no room to get puller to center of bearing, it may be damaged, also I plan to have my installer label the right shims & carrier bearing together with wire tie & paper label, same for left, and pinion shims, that way I can reinstall my old stuff without doing shim fitting if I have to return to stock for warranty work such as new tranny or engine. I was told by dealer that new gears may void warranty on tranny or maybe engine so before I try to make a $2000 claim I will put the stock stuff back in. Hope I don't have to but thats my plan.

gothikka

Redline is also good

Quick S

I agree with mustangman02232, everybody that seems to have 4.10s, seem to love'em. Talking to a few guys at work, think 4.10s is a bit much. I guess it comes down to the person itself and the driving habits. if you don't take long rides and/or don't mind listening to your engine Rev high all the time, then 4.10's is it. I'm still up and down myself. Going to look into other options as well before making the rear gear decision .

jerjan

I just installed 3.73s. They rev about 2400 Rpm @ 75mph with my stock rubber. Sometimes when driving around town I wish I had went to 4.10s, but I have to drive to Denver often (about 60 miles each way) and calculated that I would be about 2900-3000 RPM @ 75mph. That would put a lot of wear on the motor after a couple of years, So, I'll stick to the 3.73s for now.