So I have the new motor in....

a 302 bored out to a 306 pushing about 350 HP........
i have a C4 tranny


but what rear end gear ratio shouldI be using?

I want it to be Fast off the line, but i also want to be able to cruise down the highway at the same time?

Any recommendations?

 

how much driving on the freeway vs city and speeds below 65 mph? How tall is your rear tire?

I had 3.00 that gave me 3200 RPM at 80mph I wouldnt have wanted it any higher thats for sure but then I did almost as much freeway driving as i did city driving.

If you mentioned the word highway like I see you did I wouldnt want anything above 3.25s... but im a pansy. 3.25s would give you 3600 rpm at 80mph with 25" tall tire.

-Gun

 

good 70% to 80% would be city driving / below 65 mph.

As for the tire hieght..... well I havent picked out rims or even thought of that.

but i think im going to go with a 17 inch in the rear and maybe a 17 or a 16 in the front, all tires would be like a mid profile tire, definitely not low profiles.

 

well your rear tier height makes a big difference. You might get away with 3.50s based on driving style and a tire that sounds like it will be a bit larger than 25"

Lets say for fun that your tier was 27" tall and you were at 60 mph and had a 3.50 that would give you 2600 rpm but at 80 mph it would be 3500 which is not so bad

-Gun

 

well ill have to think about what tire size with what rims i want, then ill come looking for you [sm=type.gif]

 

I just asked this a couple of days ago (search is broken, so you probably didn't see it):
https://mustangforums.com/m_5238714/tm.htm

Check out the thread on axel ratio. Deja vu.

I got sound advice from Gun, but ignored my gas gauge and gun's advice to stick with the lower gear and went with a set of 3.37s. I've driven other cars with a similar drivetrain and tire and 3.50 gears are doable if it's mostly a town car. A lot of this is personal choice. I'm hoping to feel the responsivness without burning twice as much gas. We'll see after I feild test it.

Good luck.

Carlos

 

Thinking about this for me too, not to thread hijack, but I have the windsor block, abuilt c4, and do probably 50/50 freeway and city driving, and want something with traction lock... looking for some suggestions too. I'll go measure my tire height in a bit

 

I've used the linked "tire diameter calculator" for a few years and although actual tire diameters vary slightly between manufacturers, the calculator come in very handy.

http://www.users.fast.net/~blazer/tirediam.htm

Dave