4.09 gears

https://www.americanmuscle.com/ford...d-pinion-set-4091-ratio-1517.html#productInfo

Fit our cars. These must have released just recently???

FP 4.09 has been out for a while on the FP site.

Totally missed it. Potential addition the 2018 mid list which is very short. Don't drive the car enough to have a long list.

Here's our gear ratios and a calculator if you want to decide if that's something you'd consider doing. If my car was more of a time attacker and track only machine, I actually probably would. 5th tops out at 167 with 4.09's. I hate to say it but the factory ratios are actually pretty reasonable for the street.


1st 3.253:1
2nd 2.233:1
3rd 1.611:1
4th 1.243:1
5th 1.00:1
6th 0.629:1
Final drive 3.73:1


http://spicerparts.com/calculators/transmission-ratio-rpm-calculator

Thanks for that info. Do you think it would give a little more bottom end bite on the street?

Mjc1241 said:

Thanks for that info. Do you think it would give a little more bottom end bite on the street?

Click to expand...

My take on this is if you want low end, you need to tune in some low end. It'll give you mechanical advantage and help with acceleration but do just remember that you are changing the fundamental characteristics of the rev range when you change gear ratios, not "increasing low end performance", if you will.

Gotcha. Thanks for the feedback.

Have 4.10's in what is now my son's 2001 GT but the 350 is a different animal altogether. The 4.10's get it out of the hole nicely but it runs out of breath at around 5500 rpm. I would think that the lower gear would help and with the extra rooms to play with, I would not have a concern with running out of breath at the top of the Rev range.

I'd really like to do this mod...anyone confirm that these will fit in our rear ends?

they fit.