Rear end gear ratio?

What would be the correct rear end gear ratio to go with a 1966 convertible with the 200 6 cyl/auto combo?  

Check your door tag, to see what it originally had for a rear end, depends if auto or standard look under the Axle number.. then there should also be a tag on the rear axle to.  

This car has had the manual 3spd replaced with an automatic. I want to keep the auto and want to know if the 3.20:1 rear end is also the correct gearing for a 6 cyl with auto.  

my 65 automatic has 2.80:1 axle code 6 yours should have an axle code 3 on the door tag for 3.20:1 iam going the other way auto to standard (T5) you can always change the drive gear in the transmission to gfet the speedo to read correct.  

Yes it is. My 65 was changed from a 3 speed to a C-4 with the factory rearend still in the car,it is a 3:20:1. I want to keep this rearend but the only problem is they do not make the ring an pinion gear no more. I had my local auto check with Richmond gears an the don't make them an no body else doe's.
      What other car rearends work in a 65 mustang coupe. I am not worryed about the speedotometer an rearend matching up as far as corect speed,This car will never see 55 mph. Just the way I drive, " 55 an stay alive ". What will fit, a Falcom,Comet,what will fit,4 Lug from lug nut to lug nut, the hole kit an kobotel. I live in Guntersville,Alabama, Maybe some one has one for me that chande ove to a V-8. E-mail me at wlcornelius54@charter.net or Cell= 256-506-1137. Please help.  

Sorry to say that the old six-cylinder integral carrier rear ends are pretty much done for. No parts availability so you're left finding four decade (or older) used parts to use for repairs.

No one makes gears or diff rebuild parts. Most of the bearings are available though still for the 7 1/4 rear in the six-cylinder, a bit of good news.

You're right, the best you can hope for is someone with a 7 1/4 rear upgrading to V-8 driveline. I sold my four-lug parts a decade ago when I converted my '66 to V-8, so there should be something out there, it's just how long do you want to wait?

HTH...
Mark
.  
Mark Houlahan
Technical Editor for:
-Modified Mustangs & Fords Magazine
-Mustang Monthly Magazine

1965 FFR Roadster 427W/TKO-600 5-speed
1966 Mustang 289-4V/C4 Auto
1968 Mustang 4.6L Three-Valve/5R55S Auto
1990 Mustang 306/AOD
2002 Explorer Sport Trac 4.0L V-6/5R55 Auto

Could you tell me what other rearends would work.Year model. I need help  

check around, the lincoln varcilles is a common swap, and will give you rear disk, but its 5 bolt  

I would run it with what you have and change the speedometer gear.  
Bill

1966 coupe
1995 Cobra R

What year would I look for an will disk work with drum in front,5 lug is no problem. It looks like the yoke's are different so will my yoke work or interchange with the lincoln?