3.73 gears are great for a ported Eaton

[01cobravortech]

I have to say...I'm glad I finally decided to do 3.73s.

Had a badly leaking IRS cover. OEM trac-lok was failing too.

Had another Spec 3+ put in there simultaneously so I had to chill until I passed the 500mile break in barrier.

Its a fantastic mod. Based on my personal observations...3rd gear now pulls like 2nd gear pulled with 3.55s. Its just awesome to drop it into 3rd have 3rd gear pull like 2nd used to.

This simple mod has actually made driving this car fun again. 4th gear pulls slightly harder as well.

All in all...its a cost effective mod if you are tearing into the rear. It really is the right gearing for a ported Eaton Cobra.

 

[JesseSVTJames]

They suck with a whipple!!!!!!!!

 

[01cobravortech]

They suck with a whipple!!!!!!!!

I imagine at that power level they would. They seem to be just right at the 500rwhp level though. Hence why I indicated that for a ported eaton they bring home the bacon.

Got to know your car buddy.

 

[cobracide]

I'll keep the 3.55s for the highway. Can already break traction at will in two gears. As long as you can get it launched, or going from a roll. Great you can feel the extra torque on pulls.

 

[604cobra]

drag radials work well.

 

[JDUB348]

Rocking 3.73s in my SRA and love them. Just a tiny bit higher RPMs in every gear.. Love it

 

[01cobravortech]

I'll keep the 3.55s for the highway. Can already break traction at will in two gears. As long as you can get it launched, or going from a roll. Great you can feel the extra torque on pulls.

I think that's good advice. As much as I toyed with the idea of a 2lb lower I think with the 3.73s, its just going to overwhelm those rear tires and make driving this car awful. Feeling the extra torque and not having hop are great. I think my tame power level is really the limit to enjoy 3.73s.


While I don't have the whole FTBR kit, I have their diff kit, the hard mount with the 3rd bushing, and his rear tie rods. Its made an enormous difference in grip just with those parts alone. Car doesn't break loose in 2nd.

Also have to thank you for convincing me to go with the lubelocker gasket. So far over 600miles on it and hasn't leaked with the Ford Racing cover. And I've been throwing this car into corners when the opportunity comes and have tried making it hop, but no success at hopping and no leaks. Its a great product. :beer:

 

[cobracide]

Sounds like the gearing put your car right where you want/need it to be. Perfect. Good mods, need to look into those tie rods.

 

[Bruha]

Sounds like that is a good ear for the eaton. With my whipple I would like to go with 3.27's. I think it would be and all around better set up.

 

[01cobravortech]

Sounds like that is a good ear for the eaton. With my whipple I would like to go with 3.27's. I think it would be and all around better set up.

Yea I think it would be a great mistake to do 3.73s with any of the bigger blowers and even the lower/pullet setups.

 

[TurboGA]

Good topic. I have a SRA with 3.73 gears on my 04 cobra. Car runs good alot of pep on take off at the track but I did notice it lost 3 mph from my 3.55. Same tires 26X11.50X17. My car has a 2.3 Whipple with 3" upper and stock lower (16 lbs boost), LT's, X pipe, stock motor. It seemed to pull harder at top end with 3.55 gears. I'm still scratching my head on this one. I have ran it on same temp days as before but the mph is still lost ever since the 3.73 gears. Any Ideas???:??:

 

[svt4me38]

Big blower guy here! And I love my 3.70s, on the street it's a joke but I love them at the track with my 28s.
For me 3.70s have always been the magical gear!

 

[SVT-BansheeMan]

Crazy how we differ. I have 4.10's sitting waiting to go in. I cant stand my 3.73's with my whipple. Must be the extra weight and tire height of my red fridge.

Any of yall tried 4.10's on a 28" tall slick?

 

[702lightning]

I agree on the 373's up to about 500rwhp. Great gears for it!

 

[P49Y-CY]

love my 3.73's :rockon: 2.80 unported eaton


I also love my 4:10s on my 2.93 unported eaton, but if I had to choose either or, I think I would probably go with the 3.73 because it is more comfortable on the highway.

 

[Senkak]

Big blower guy here! And I love my 3.70s, on the street it's a joke but I love them at the track with my 28s.
For me 3.70s have always been the magical gear!

I agree.
3.73s work great with the 28" drag slicks.
On the street with 26" DRs it is tough to keep the tires planted.

 

[Shadow Grey 03]

I agree.
3.73s work great with the 28" drag slicks.
On the street with 26" DRs it is tough to keep the tires planted.

I agree. I went and tried a 3.90 with a 28" DR and it likes to spin on the street. It would work really well with a bias ply 28" though :rockon: Maybe a 27" bias ply as well.