All Small Six Which rear end for '65 Mustang Fastback w/ performance 200

[Goldie]

Hello,

Many of you have commented or helped with recommendations for our 200 build of "Goldie". After a few months of trials and tribulations, I'm happy to report that she is running incredibly strong and made the Long-hauler journey on the Hotrod Power Tour last week... 1400 miles, 4 states, and 5 venues. Out of 6000+ registrants, we were the only performance 200 that we could find, and the car got loads of attention. The trip was amazing and the car didn't miss a beat! Ran strong, and even had power to spare at 80mph on the highway. We couldn't have been happier.

One thing we want to do next is convert to 5-lug axles and a Ford 9" rear-end with 3.55 gears. We have the stock rear-end now with 2.83 gears and while the car's performance is adequate with approx 200-225hp, I'd like a little more "launch" power off the line. We have a C4 cruise-o-matic with 2500 stall converter.

Any recommendations are welcome (you guys have been a Godsend to us during our entire build... thank you!!), and if anyone might have a 9" rear-end for sale (complete or less carrier), we might be interested in purchasing. Let me know what you have. Also contemplated putting in a Tremec T5 trans, but the cost of that isn't in the budget this year.

Many thanks! Here's a quick clip of the car on the Power Tour at the Rockingham Speedway venue.

 

[Invectivus]

Dana 60. JK, I personally think an 8" is enough, a 9" is a lot heavier and that just makes life harder.

 

[rocklord]

An 8" rear end would be plenty for your 200.
A 9" has more parasitic loss.

 

[Jmustang_65]

If you go 5 Lug you will need adapters or need new wheels. I'm sure you thought of that. Mavericks had Ford 8 inch with 4 lugs. Or you will need a 65-66 axle housing and get the axles redrilled to 4 lug.
I would think an 8 inch would be sufficient with 3.55/3.73 gears. That's what I went with. Got all cleaned up, powder coated black and installed 3.55 posi with rebuilt drum brakes.

You can also check out quickperformance.com for a center section. Great prices.

Here's a couple housings.

1966-1970 FORD MUSTANG 8" REAR HOUSING - 54 1/2" | eBay

1967-1970 FORD MUSTANG 8" REAR HOUSING. THIS IS A USED ORIGINAL FORD HOUSING.

www.ebay.com

1965 1966 Ford Mustang V8 8

Condition Used Description Rear end housing out of a 1965 Mustang with a V8, 5 Lug, 8”. This is in good condition for its age, some surface rust as expected could use blasted. I believe this will also fit a 66. Please view pictures with care; comes as shown with only what is shown.

www.fatmansgarage.com

 

[65coupei6]

I went with an 8" w/Tracloc. But if I were to do it again. 8.8 from an Explorer.

 

[Jmustang_65]

Yes that 8.8 is a good option and can he bad for cheap with disc brakes and posi. Just needs to be cut to length on the one side.

 

[bubba22349]

Hi Goldie, the 1965 & 1966 Mustang 8 Inch Axles are of course a direct bolt in in place of the 7 ¼ Inch axle. This info is from one of my older Posts about Rear Axels. For a 9 inch rear Axle the one to look for is from one of the 1957-1959 Full-Sized Ford & Mercury Passenger Cars (and few others) see more details of those that can Fit and Work below. These 9 Inchers will have a housing width of 52 ¼" across, flange-to-flange (same as the 1965-1966 Mustang 8-inch rear end has). Plus these rear ends also share the same leaf-spring perch locations as the 1965-1973 Mustangs with a 43-inch distance center-to-center. They are a direct swap for a 1965 to 1970 Mustang, it will give a 1967 to 1970 Mustang slightly more wheel well clearance. These "narrow" 52 ¼ housings will also fit in the 1971 to 1973 Mustangs but wider wheels & tires will be mandatory unless spacers are used with the stock wheels to space them back out.

The 1957 to 1959 Ford Big-Car rear ends came in two housing configurations a Large axle bearing housing, or the Medium axle bearing housing this is the same bearing size as the early Mustang 8-inch rear end has).

(1) The Large Bearing Housings are a little more rare and can be found in the 1957 to 1959 Ford Station Wagons, the 1957 to 1959 Ford Rancheros, and the 1957 to 1959 Ford Sedan Delivery's. Also that with a little work the * 1958 to 1960 year model Thunderbird 9 Inch Axels can also be used see the below note.

(2) The Medium Axle Bearing Housing's will be found in all the other 1957 to 1959 Ford Big Passenger Cars.

(3) Many other years of 9 Inch Axles can also be used by Narrowing them to the Above Measurements or a little narrower if you going for bigger rear Wheels & Tires.

Note that *The 1958 to 1960 year model T-Bird 9-Inch Rear Ends measures 52 ¾" inches across Flange to flange this is only a ¼ of an inch (per side) wider than the other early 9-Inch Rear Ends. But it dose have spring perches that are set at 36-inches apart, so the spring perches will also need to be cut loose from the housing and moved out to a distance of 43-inches between them and then be re-welded to the axle housing tubes. The T-Bird leaf-spring perches are also made of a much "thicker" material. I used a 1958 T-Bird 9 inch in my 1941 Willys A/G build it had a set of Custom 31 Spline Axels, Differential was out of a 1969 Mustang Mach 1 Cobra Jet, made a Custom Coil Spring / Shock set up and Custom set Traction bars (based on what the 1964 Ford Fairlane A/FX cars used) this was in late 1967 to 1969. Good Luck in the hunt.

 

[Goldie]

If you go 5 Lug you will need adapters or need new wheels. I'm sure you thought of that. Mavericks had Ford 8 inch with 4 lugs. Or you will need a 65-66 axle housing and get the axles redrilled to 4 lug.
I would think an 8 inch would be sufficient with 3.55/3.73 gears. That's what I went with. Got all cleaned up, powder coated black and installed 3.55 posi with rebuilt drum brakes.

You can also check out quickperformance.com for a center section. Great prices.

Here's a couple housings.

1966-1970 FORD MUSTANG 8" REAR HOUSING - 54 1/2" | eBay

1967-1970 FORD MUSTANG 8" REAR HOUSING. THIS IS A USED ORIGINAL FORD HOUSING.

www.ebay.com

1965 1966 Ford Mustang V8 8

Condition Used Description Rear end housing out of a 1965 Mustang with a V8, 5 Lug, 8”. This is in good condition for its age, some surface rust as expected could use blasted. I believe this will also fit a 66. Please view pictures with care; comes as shown with only what is shown.

www.fatmansgarage.com

Thanks for sharing the ones you found! We appreciate it.

 

[Goldie]

Hi Goldie, the 1965 & 1966 Mustang 8 Inch Axles are of course a direct bolt in in place of the 7 ¼ Inch axle. This info is from one of my older Posts about Rear Axels. For a 9 inch rear Axle the one to look for is from one of the 1957-1959 Full-Sized Ford & Mercury Passenger Cars (and few others) see more details of those that can Fit and Work below. These 9 Inchers will have a housing width of 52 ¼" across, flange-to-flange (same as the 1965-1966 Mustang 8-inch rear end has). Plus these rear ends also share the same leaf-spring perch locations as the 1965-1973 Mustangs with a 43-inch distance center-to-center. They are a direct swap for a 1965 to 1970 Mustang, it will give a 1967 to 1970 Mustang slightly more wheel well clearance. These "narrow" 52 ¼ housings will also fit in the 1971 to 1973 Mustangs but wider wheels & tires will be mandatory unless spacers are used with the stock wheels to space them back out.

The 1957 to 1959 Ford Big-Car rear ends came in two housing configurations a Large axle bearing housing, or the Medium axle bearing housing this is the same bearing size as the early Mustang 8-inch rear end has).

(1) The Large Bearing Housings are a little more rare and can be found in the 1957 to 1959 Ford Station Wagons, the 1957 to 1959 Ford Rancheros, and the 1957 to 1959 Ford Sedan Delivery's. Also that with a little work the * 1958 to 1960 year model Thunderbird 9 Inch Axels can also be used see the below note.

(2) The Medium Axle Bearing Housing's will be found in all the other 1957 to 1959 Ford Big Passenger Cars.

(3) Many other years of 9 Inch Axles can also be used by Narrowing them to the Above Measurements or a little narrower if you going for bigger rear Wheels & Tires.

Note that *The 1958 to 1960 year model T-Bird 9-Inch Rear Ends measures 52 ¾" inches across Flange to flange this is only a ¼ of an inch (per side) wider than the other early 9-Inch Rear Ends. But it dose have spring perches that are set at 36-inches apart, so the spring perches will also need to be cut loose from the housing and moved out to a distance of 43-inches between them and then be re-welded to the axle housing tubes. The T-Bird leaf-spring perches are also made of a much "thicker" material. I used a 1958 T-Bird 9 inch in my 1941 Willys A/G build it had a set of Custom 31 Spline Axels, Differential was out of a 1969 Mustang Mach 1 Cobra Jet, made a Custom Coil Spring / Shock set up and Custom set Traction bars (based on what the 1964 Ford Fairlane A/FX cars used) this was in late 1967 to 1969. Good Luck in the hunt.

Terrific info Bubba! As always, you are always taking my education to a new level! Thank you very much. I guess this isn't going to be a simple swap... a lot to consider, but great to have this information when we make our final decision.

So, you know our build pretty well. Would you go with an 8" or a 9" (if it were your car)?

 

[DannyG]

I went with the Maverick 8", allows me to choose my gear ratio( 3:40) and keep 4 lugs.
I'll admit I went a little crazy/weird on the front, V-8 Mustang spindles/brakes,shelby drop/suspension with the hubs/rotors drilled back to a 4 lug pattern. Love the 4 lug look...
Congratulations on the Power tour, jealous !
Dan

 

[bubba22349]

The 8 Inch is as was mentioned in the some of the above posts plenty strong and stock can handle 400 Plus H. P. (more with some tweaks and Axle upgrades) the 8 Inch also uses the same size Medium Wheel Bearings and 28 Spline Axles as many of the 9 inch axles did. The Explorer Disk Brakes can be used on both the 8 or 9 inch Axles too, there are several Possi / Limited Slip and Locker's made for both an 8 or 9 Inch. Also as was mentioned above the 9 Inch will add a somewhat more weight and uses a little more power to turn it compared to the current 7 1/4 Inch or one of the 8 Inch Axles. So to me it mostly comes down to the amount of Power you plain on making & the Gear Ratio that you plan to use, and if that is available in the 8 Inch Gear Set's, there is fairly good coverage of ratio's for them and their cost will be lower over all. The 9 Inch dose have more Gear Ratio's made for them than any of the other Axle's and they excel in their strength. To my knowledge the only 9 Inch Axles that were ever used in any stock 1965 & 1966 Ford Mustang's were those in the 1965 & 66 Shelby GT 350's and I am fairly certain that they used the 1957 to 1959 Big Ford Car width of 9 Inch in them.

 

[Goldie]

I went with the Maverick 8", allows me to choose my gear ratio( 3:40) and keep 4 lugs.
I'll admit I went a little crazy/weird on the front, V-8 Mustang spindles/brakes,shelby drop/suspension with the hubs/rotors drilled back to a 4 lug pattern. Love the 4 lug look...
Congratulations on the Power tour, jealous !
Dan

Sounds like a nice set up Danny! Thanks for the recommendation. We also have suspension upgrades (Open Tracker roller) and the Shelby drop in addition to front and rear sway bars.

 

[Frank]

Decent range of gear ratios available for the 8".

Ring and Pinion Gears at Summit Racing

Find ring and pinion gears from Strange, Richmond, Ford Racing, Motive, Yukon, and more at Summit Racing. Order your new ring and pinion gears now!

www.summitracing.com

 

[65coupei6]

If you don't want to go 8.8 from an Explorer.

Then get a 8" inch from a 65/66. Then get a trac loc from :

8 and 9 Inch Ford Rears, Custom Built

Ford Rears Custom Built for Street to Race Applications. From stock Trac Loc posi to full-spool, all-out race third members. Check out our..

8and9inchfordrears.com

Follow this up with an Explorer aluminum driveshaft and you are good to go. BTW, this is my current setup. Also don't forget the driveshaft safety loop.

 

[78_200_C4]

3.25 gears with a C4 + 14" tires are good in town and on the freeway with a 200.
I drove my 200 from California to Missouri pulling an aluminum boat. I drove it there for 11 years then towed the boat back to California. Previously I ran the same 8" 3.25 rear end behind a 302 C4 in a 62 Ranchero for ten years.

 

[78_200_C4]

You might want to consider a 5 speed along with a lower geared rear end.
The 3 speed C4 can shift a 200 out of it's power band. You want to keep the rpm up when shifting not wait for the 200 to get back in it's power band,
A stick shift also uses less power than a C4.
I have 6 forward gears and I love it when I keep the rpm up after shifting.

 

[65coupei6]

This might be helpful:

8.8" narrowed now u bolts slip on tapered side

I have a 1967 that I am in the process of swapping (i6) to a 5.0L, 4R70w and 8.8" from a 1999 Mountaineer. The motor and trans are in. With some help from friends, the 7.25" rear end has been swapped for the 8.8". I had a local shop narrow the rear end, to cut down the driver side and make both...

www.vintage-mustang.com

 

[78_200_C4]

A 65-66 Mustang 4 lug rear end out of a stick shift car would have lower gears + bolt in with out any modifications.

 

[Wayne clark]

Sounds like a nice set up Danny! Thanks for the recommendation. We also have suspension upgrades (Open Tracker roller) and the Shelby drop in addition to front and rear sway bars.

For what it's worth, I put a rear sway bar on my 67 vert that I had to remove when I installed the dual exhaust . When I removed it I found one of the square u bolts that is inserted in the frame rail had torn the rail some .
You may be better off with a pan hard bar .if you have not replaced the rear suspension bushings yet it's well worth the effort.

 

[chad]

C-4: least parasitic of the autos (I like the AOD better for the od).
WC (world class) bent8 T-5 can B adapted to the smaller bell 3.3L (see AA in Paso Robles)

I believe there's more aftr mrkt support for the 8.8 ford rear (perches, axels, gears, etc) than the 8. Might not matter in ur case (one
found is perfect 4 U). Get the info together 1st, then compare the 2? Buy after? Then order prts...

Isnt customizing fun (research, fab, source/purchase/return, repurchase, try/assembly, throw away, break, etc