Looking for options to do a 4” to 4.5” bolt pattern swap all around and brakes.

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nktrnljerms

nktrnljerms

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I have a stock '68 Barracuda Convertible V8. Looking to the group for some build and replacement options (and price-saving).
Good examples, stay away from, or pitfalls. Don't do's.

- 7.25 rear
- Disk conversion or stay drum out back

Reasons: Updated stopping/safety and some wheel options for a nice street cruiser with a bit of upcoming HP upgrades.

(Not interested in QA1 prices or parts. This is not the car (or my wallet ;) for those types of upgrades)

Screenshot 2024-03-20 at 12.45.56 PM.png
 
For the front, the usual '73 and up single-piston discs. Make sure you also get longer brake hoses ('69 Camaro or F/M/J) and rear-mount the calipers for sway bar clearance.
Doctor Diff- good prices, good parts, excellent customer service.
10.95" Front Disc Brake Kit (Stage 1)
If by chance you already have the Kelsey-Hayes four piston discs up front, just use modified Mustang rotors.
Using mustang rotors for 4.5" bc
For the rear I'd hunt down a '73-'76 A body 8.25 rear, a bolt-in other than the shock plates and U bolts, and driveshaft length.
If you insist on keeping the 7.25 (a weaker rear that may not stand up to any serious power), I would again turn to Doctor Diff. He offers an axle package that changes the bolt pattern to 5x4.5, and gives you the option of new drums with the correct bolt pattern.
Mopar Axle Pkg 7 1/4" A-Body 5X4 1/2" Bolt Pattern (pair)
He can also set you up with all the other little odds and ends you wil need to complete the swap: master cylinders, combination valves, lines, and a power booster and brackets if you so desire.
 
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Dr. Diff has lots of options and is highly recommended. If you want to do the DIY method, going to the 73+ front disc setup gets you the 4.5" bolt pattern and good stopping power. For the rear and, an 8.75 is nice and has the most options but they tend to be quite pricey. For your intended use an 8.25 would fit the bill much more affordably and is plenty strong. The drums in the rear are certainly sufficient unless you are doing something severe like autocrossing.

Hah! Treed by the professor!
 
Oh nice, Thanks.

I did not think about the 8.25 swap. My Dart pictured above has that already so maybe just a trade/swap is in order.
I have an 8.75 on hand and in the works for the Dart.

Thanks for the all the info.
 
I have always upgraded to 73-76 A body front disc set up & 8 3/4 rear 10 in. drum with NO power booster, that way I don't have to worry about low vacuum at idle, go to doctor Diff and look what he has & call him if you have questions, great customer service. I buy some parts from him just not kits because I look for deals, it just takes time to find, and you have to clean old parts. Nice looking cars. If you go with 8 3/4 you can change gears sets to have some fun or for freeway long distance trips. If you go with 8 1/4 just pick gears for the type of driving, you plan to do. both rears are getting hard to find.
 
I'm working out what to do on my duster for a rear end. can't find much older than mid 90's here. '93-'10 ford rangers are just under an inch and a half wider drum to drum than the stock A body 7.25", and YJ wranglers (the square headlight version) are supposed to be about the same width (58.5"). the dana 35 in the wranglers have a smaller axle tube diameter, so they likely will work with the stock 7.25" shock plates. either will require cutting off the old spring perches and welding new on. the Dana 35 is a 7 5/8" ring gear, the rangers came with either 7.5" or 8.8" ring gear rears. the 8.8 will take just about anything you can throw at it, street car wise. the ranger pinion is offset about 2" from the centerline of the vehicle.

stock '73-76 A body disc brake cars had 11" front discs and 10x2.5" rear drums. '87-89 wranglers had 10x1.75" drums, '90-95 had 9x2.5". 9x1.75" or 10x2.5" rear drums. Also read up on this thread about explorer rear ends:

8.8 swap
 
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