3.27 to 3.55

[dlsdj]

Just wondering if a speed-cal is needed for this change?

 

[Sam98]

Just wondering if a speed-cal is needed for this change?

If you don't mind your speedometer reading about 71 when you're really going 65 and you don't care about the extra 8.5% mileage on the odometer, then the answer is no. Also, if you have a 99+ Mustang the answer is no because you can compensate for the gear change by changing the scalar in the PCM. Otherwise, you will need it.

 

[stangman]

why are you doing such a small gear change?????? i've driven a buddies car with 3.55 & then i jumped in my car & couldn't tell a difference at all. if this a upgrade for just a little more get up & go, your would be better to spend your money on at least 3.73's imo

 

[Bone Racing]

yes its needed for ANY CHANGE....
but that gear change is very small...u prolly wont notice it

 

[03-s281]

3.55 is a good street gear.
The change in the first 3 gears with 3.73's vs 3.55's is not significant.
You would notice a little in 4th and 5th.
If you dont hardly ever hit the strip I wouldnt worry.
You'll still be coming out of 1st @ 15mph in normal driving.
I like mine, even though I'm fixin to go 4.10's

 

[decoy562]

I would personally go with 3.73's or 4.10's.

 

[cold96snake]

4.10's!!!

 

[STEVEATFORD]

i installed 3.55 in my car and then installed 3.73 big dif in the 3.55 vs 3.73
3.55 is a waste of time and money

 

[2k2SilverBullet]

how do you change the SCALAR, and what is that

 

[Blue1]

I have 3.55 gears in my '91 5.0 auto and they are awesome. I got on the highway and see 80+ frequently (early fast lane rush hour around here) and the 3.27s I had in there are probably worth two mpg at those speeds, but it is a nice compromise.

Given that I have only 5oo mile on my new GT (5-speed with 3.27s) I have noticed a severe lack of torque (relative to the 5.0) that would require 3.73s at least.

Blue1

 

[forpit2000gt]

don't waste time with 3.55, go at least 3.73. 4.10s still not to much. Please don't let me hear about fuel mileage. I also find it is easier to drive around town with 4.10s. Highway driving is fine too.

 

[COramprat]

The 3.55's are a good gear for th 5.0 engines but for the 4.6 the minimum I would go with is 3.73's.

 

[00s281sc368]

The 3.55's are a good gear for th 5.0 engines but for the 4.6 the minimum I would go with is 3.73's.

It depends how much power you make...

 

[forpit2000gt]

I think we are talking about a NA Mod motor. Even If I had 433 rwhp, I would go with 3.73.

 

[COramprat]

It depends how much power you make...

I understand that. Pretty much a given if you are planning on S/C or turbo, go with 3.73's. I just think 3.27's to 3.55 is not going to gain a whole lot in any application using the 4.6. The 5.0 is a lower revving engine so 3.55's work better in most cases there. And if you decide on 3.73's or 4'10's then the Speedcal or computer flash is a must.