Advice on Gear Ratio after adding significant hp.

[Milford Mustang]

New to Mustang Performance. I re-powered my 95 GT with an old school 331 stroker. I have 94 Cobra Heads, Ford 302E cam, EDLEBROCK 650 carb and Intake. I believe I have added significant HP over stock (have not yet dyno 'ed). My question is regarding rear axle ratio. I want more punch from a stop, but I am not going to drag race. This is an around town cruiser with some limited highway time. From reading dozens of opinions, a 3.73 seems to be a sweet spot with a stock GT. With my added HP do you guys think will the 3.73 be too tall? Like I said my interest is more umph coming off the line for that fun to drive feel.

 

[95opal]

Light to light 410s would my my choice

 

[Terrorist 5.0]

I am the odd one out here, but how do you normally drive your car? 4.10’s for a stock GT is a lot of fun when you punch it, but is awful to drive normally, and highways are a drone fest. With your setup, if you care about normal driving at all, 3.55 at most. Keep in mind, this is assuming you are running a stock T5. First gear is going to be a burnout gear no matter what you do unless you have 2.73’s.

Ring and pinion is subjective though. Everybody likes their own thing. I for one, even on a stock 95 GT, want to put in some 3.31’s. I like my gears to have some legs. I like to pull up to 110-120 MPH so the 3.31’s put me right at the top of 4th gear before I let off.

Consider these things carefully.

 

[96blak54]

I to am a fan of gears that have some legs! Ive had them all, 4.10, 3.73, 3.55, 3.27, 2.73. I fall into the compromised category by running a 3.55.

Truth be told, it really depends on the engines power range. My 5.4 2v loads of off idle torque. Far more low end torque than upper rpm horsepower and the stock 2.73 rear worked very well with its power range. And when in 5th gear the cruise rpm was very low. Still had gobs of pulling power too. I swapped it to a 3.55 which made for a fun ride with short sprints, but the 5th gear cruise rpm was to high for my liking with this engine.

If the engine was short on torque and loved rpm like a 289, I think a 3.73 or 4.10 coupled with a 5speed manual trans would be the ticket.

A got a local friend with a supercharged 5.4l 4v F150 that runs a 3.55 rear gear and a chevy 3speed automatic trans. The chevy trans holds up to the monstrous torque and the truck feels like a rocket ship. The tall gearing makes that engine work!

 

[Milford Mustang]

I to am a fan of gears that have some legs! Ive had them all, 4.10, 3.73, 3.55, 3.27, 2.73. I fall into the compromised category by running a 3.55.

Truth be told, it really depends on the engines power range. My 5.4 2v loads of off idle torque. Far more low end torque than upper rpm horsepower and the stock 2.73 rear worked very well with its power range. And when in 5th gear the cruise rpm was very low. Still had gobs of pulling power too. I swapped it to a 3.55 which made for a fun ride with short sprints, but the 5th gear cruise rpm was to high for my liking with this engine.

If the engine was short on torque and loved rpm like a 289, I think a 3.73 or 4.10 coupled with a 5speed manual trans would be the ticket.

A got a local friend with a supercharged 5.4l 4v F150 that runs a 3.55 rear gear and a chevy 3speed automatic trans. The chevy trans holds up to the monstrous torque and the truck feels like a rocket ship. The tall gearing makes that engine work!

Thank you I am leaning towards the 3.73 as this is meant to be a fun car but still thinking hard on the 3.55

 

[Milford Mustang]

Ok, 3.73 wins. Install date is Augst 1st. Thanks guys.

 

[ttocs]

what heads/cam did you put in it?

 

[Terrorist 5.0]

We should be asking, what trans are you running? Thus far, I think we’ve all assumed you are running a stock T5.

With 3.73’s and your power, first gear is a burnout only gear, unless you are on a strip with slicks. No question about it.

The Mustang T5 in my opinion has a slight problem for higher power applications. First gear is just too steep. With a ring and pinion upgrade, you can either get a really good first gear and a long second through fourth, or a really short and useless first gear, and a good second through fourth.

It’s your car and all the power to you, but if you are running a stock T5, I would really weigh your options before you commit.

 

[Frank.JD.Perez]

I had 373s with stock hp and with the built motor i had i more or less doubled the factory hp (190ish to 350ish) and the 373 was fine

 

[Terrorist 5.0]

I had 373s with stock hp and with the built motor i had i more or less doubled the factory hp (190ish to 350ish) and the 373 was fine

Stock T5? How was first gear when you hit it?

 

[Frank.JD.Perez]

T45

 

[Daryl]

347 stroker w/ TKX 5-speed and 3.55 rear gears. Sort of high on rpm’s ay highway speeds. Kinda wish I had gone 3.31’s or even a tad taller. Would like more legs between shifts