rear end questions

Decurion

Member
Sep 28, 2006
353
0
16
Livonia, MI
Im building a 65 Falcon that originally came with a 6 cyl, but Im putting in a 302 and was going to put an Explorer 8.8 in it, but after reading a lot of info about that swap in this forum, it looks like Im going to 86 that idea. Ive got a few questions on what to replace it with.

1. Does anyone have a chart with the overall axle widths and perch widths for various cars?

2. Roughly how much would it cost and what would it take to make the 8.8 useable?

3. Can the 8.8 discs be bolted onto the 9" housing? My guess is no F-in way. I have a 9" housing thats been laying around forever that needs to be narrowed, if i want to go the 9" route.

4. What about axle shaft lengths? If I use the bare 9" housing I have, I can easily get a centersection from a truck or something (my buddy owns a junkyard), but correct lenght axleshafts I would have to find on my own.

thanks a bunch in advance!

ps if anyone else likes the falcon/comets and knows of a useful forum, let me know, cuz I sure havent been able to find one yet!
:SNSign:
 
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Narrowing an 8.8 costs the same as a 9. In either case, you can choose axle/bearing ends to fit what ever brakes you decide to go with. Custom axles will run you about $300 here. Junk yard axles are extremely hard to come by in the correct length. I narrowed an Explorer 8.8 for my Ranger, total cost was around $700-800, including the purchase price ($100), Strange 31 spl. axles ($300), 9" style bearing ends ($80), aluminum girdle cover ($130), and labor ($150)
 
A 9" would be overkill for an I6 (unless it was really built to the max) and would take away power from an engine that probably doesn't have enough already. If I'm not mistaken I think the 65-66 Mustang 8" would work too. There are some axle charts available on the internet. I'll see if I can find one.
 
it HAD an I6 in it originally, car is being painted now, will have mostly stock 302 with gt40 exploder/cobra heads and roller rockers. I forgot about the granada rears, that may be a good way to go. Should be pretty easy to come by too.
It makes me so mad that I bought an exploder 8.8 thinking it would work, then to find out it doesnt (without a lot of work anyway). At least I didnt pay much for it.
 
Info on rear ends --particulary 9-inch rears;

1. http://www.ultrastang.com/Rearinfo.asp?Page_ID=3

2. http://www.ultrastang.com/Rearinfo.asp?Page_ID=2

3. http://www.ultrastang.com/Rearinfo.asp?Page_ID=5

4. http://www.ultrastang.com/Rearinfo.asp?Page_ID=9

Six cylinder engines, particularly the 200, 250 or 300s have a lot more power/torque than people give credit. In the case of the 250, it's only 39 cubic inches smaller than a 289, and a 300 six is only 2 cubic inches smaller than a 302, but is 11 cubic inches bigger than the 289.

The 9-inch rear end housing in the following link came from an '80 model Mercury Monarch that was powered by a 250 in-line six cylinder;
http://img172.imageshack.us/img172/3282/monarch9inchim1.jpg

The '80 Monarch drum brake 9-inch rear was the basis I used to convert to Cobra rear discs to replace the '79 Versailles factory disc brake rear I had under my '68 Mustang;
http://www.ultrastang.com/images/2006/cobrabrakehosemount0243cf_2.jpg

Few people who get bitten by the Mustang bug leave their cars stock. There's always that drive to make it faster, better, more powerful. "Over Engineering" the parts of your car to handle whatever power plant you install (or may possibly install in the future) just keeps you from having to upgrade parts (spend even more money) over and over everytime you go up another power level.

There's plenty of debate in opinions between 8-inch rears vs. 9-inch rears as to what's needed or not needed. Many argue that the 9-inch is a "heavy" rear end but in reality, for example, a '65/'66 Mustang drum brake rear end is only 24 lbs. lighter than a comparably equipped drum brake 9-inch rear from a '57-'59 Ford big car. That equates to 12 lbs difference per side --in relative terms, that's not much more, but the strength capabilities will be vastly greater with the 9-inch over the 8-inch.

But, as always, it all goes back to the owner in their preference in what they deem is "right" for them and for their particular application.
 
Your not gonna find a junk yard 9 inch that will fit the falcon the way it should..A real good fit is the maverick 8 inch. I installed a curries 9 inch version of the maverick axle in a 64 sprint.. The rims are 15x8 with a 4 inch backspace mounted with 235/60/15 MT drag radials.. This is about a good a fit your gonna get without massaging fenders unless you have a drag race only car.....shure you can go with a granada axle and a differnt deep backspace rim but your limited in rim choices at that point unless you want stock rims and 205 tires.
104250.jpg

104251.jpg


This car has the maverick 9 inch from curries with strange ss 31 spline axles and a 5.14 gear with ful spool. stock drum brakes, stock leafs, lakewood 50/50's and lakewood traction bars..
 
I would suggest contacting Currie rear ends. They are one of the leading rear end fabricators around. They can put together any combination for you. new axels (not forged) are around $175 each. With the 302, an 8" is more than adequate. We're running a 347 stroker in our 65 mustang and we are using an 8" with 3.55 ratio and Eaton Tru Trac. Currie, along with other shops all felt the 8" was more than adequate. Currie can more than likely tell you what the measurements for spring perches, etc should be.