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best rearend for the crown vic swap

Posted: January 26, 2012, 1:43 pm
by SLICKCOLLECTOR
i have started the crown vic front suspension swap into a 1965 shortbed frame. the front suspension is bolted in and i mocked up an FE block and a C6 combination and placed the rear crossmeber and drilled the new holes for the correct length and have the motormounts for the FE engine done and the mocked up engine pulled out. still to do is making the brackets for the control arms and determining the best rearend for my combination. i am running a 400-450 hp 428 with a built c6 in this truck to start with and then may add a 427 fe stroker for a few more horses. i am opting for a 9 inch ford rearend for durability reasons and have a complete 9 inch from a 73 ford . it is a N case 3.50 tracloc 31 spline rearend. the width of this rearend is 65.25. the crown vic front end measures appx 67.25. the early slick rearends have only 28 spline axles and the narrow drum brakes and are 61.25 wide. i have a 67-72 9 inch rearend that is setup for a slick and is a N case and 3.50tl gears and 31 spline. i am going to use either the 61.25 wide rearend or the 65.25 wide 73 f100 rearend. i see it is possible to get 1.5 inch wide wheel adaptors and end up with 68.25 wide axle for the rear with a matching 4.5 bolt pattern with the front axle. o/w opt for the 61.25 wide rearend and order some new 31 spline axles with a 4.5 inch bolt pattern. i am not familiar with the new style wheels and only have the wheels & tires that came with the crown vic front axle when i removed it a local pickn pull. if i use the narrow axle i am going to have to use wheels that have a lot differnet off set on the front versus the back. i am looking for some options from the others that faced this same issue. thanks.

p.s. : i can't wait to see how this pickup drives.ImageImageImageImage

jim oberg
eudora ks

Re: best rearend for the crown vic swap

Posted: January 26, 2012, 9:03 pm
by Toyz
Late model Mustang applications with the "FWD" type factory offset are a good fit for the front, and are usually available in varying widths. Bullitt wheels are a personal favorite for availability and reasonable cost (as well as the nostalgic look), and are made in 8.5 and 10 inch widths. They are also available in aftermarket replicas. Any wheel design with the offset for the S197 Mustangs is a good fit IMO.

Paul

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 7:56 am
by Brian Taylor
Steve may chime in here but he did the CV swap and used for the rear from an 80 F100 which has the 5 on 4.5 bolt pattern factory and was a good width to match the CV width. Steve can give the exact inches and he will use Mustang mag wheels.

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 8:43 am
by SLICKCOLLECTOR
i read that post and most others related to ther CV swap. i have a 1980 2wd f100f150 and it has a 5 1/2 inch bolt pattern. not 4 1/2. i have never seen a 4 1/2 in a ford truck. the width on a 1980 is 4 inches wider also but still a couple of inches less than the 67 inch width of the crown vic front axle. the 65 1/2 inch width of the 73 up ford truck would require a adaptor to 4 1/2 inch that is an 1 1/2 wide. that leave the rear axle at 68 1/2. to wide in my opinion. at least an inch wider than the front. the front axle is about the limit to the width i want to go. i would like to run wider tires on the rear than the front. the 67-72 axle is 61 1/2 and to narrow to try to adapt to the 4 1/2 inch bolt pattern. i don't like the idea of having huge spacers behind the wheels or adaptors. i found a machine shop who will redrill my axle bolt pattern from the current 5 1/2 to 4 1/2 but another machinist mentioned the drilling of the brake drum holes and mentioned the hardness and cast iron being a problem. i have a 67 galaxie rearend i pulled this spring that has the 4 1/2 inch bolt pattern and am going to see if they are interchangeable with the drums on a truck save for the bolt pattern. all of this makes the 98 up 8.8 explorer disc brake rearend swap look more and more friendly . what kind of emergency brake setup does this rearend have. if i keep a ford truck rearend that problem solves itself. thanks.ImageImageImageImage

jim

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 8:53 am
by cooter
currie and moser have e brake cables for the explorer. As for the diff, pick a rim and tire, mount it under the truck and find a diff that matches. Torino, ltd are also likely donor vehicles. I would use a way wider rear rim with a deeper face to make it look better

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 9:38 am
by longcabjohn
The emergency brake on the explorer is a small drum brake setup on the inside of rotor, looks just like what you have only smaller.



Johnny

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 10:04 am
by 36truck
Ford did build the F100 in the early 80's with a 4X 4.5 bolt pattern.

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 10:07 am
by 62galxe
as far as the 4 1/2" lug spaceing it was a light duty f100 thing
** 1980-1983: F-100: GVWR: 4700/5000: with Power Brakes: 10inch brakes: 5x4.5

1980-1983: F-100: GVWR: 5150 and 4700/5000 with manual brakes.: 11 inch brakes: 5x5.5

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 12:48 pm
by unibody madness
Ok so one of the next projects I will tackle, is the CV front.
My question is what is wrong with the crown vic rear 8.8? I already aquired the set up, and thought it a win, win. It comes with disc rear, same track width, same rims all around, strong enough to withstand police/highway patrol abuse.. what am I missing? :hm:

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 1:04 pm
by Gritsngumbo
I'm pretty sure It's even wider than the front. Much too wide for most taste.

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 1:55 pm
by Rusty 63
The '03-'07 cv rear is much too wide to fit our trucks.

Take a look thru Randy's (carcrafter22) build thread on one of the 67-72 forums. If memory serves, he used a 91 cv rear which worked perfectly.

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 2:17 pm
by Gritsngumbo
If I'm not mistaken, the early 90's CV rears are 5 in 5.5 so the axles would need to be redrilled to 5 on 4.5 for fronts and rears to match. That's why I'm going with the early 80's F100 diff. They are surprisingly easy to find.

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 3:23 pm
by unibody madness
Thanks guys
Grits what specific years will fit ? do you have any pics?

Rusty thanks, I just did about an hour of post jumping and found CC used a 93 cv rear, however as you know he is seldom happy and tends to keep moving things around did he move past the 93?
I get head aches after too many hours on that site.

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 6:15 pm
by Rusty 63
After the '93 cv (thanks) rear, he went to a t-bird independant rear suspension. It's hard to read on the ford truck sites, try the 4btswaps site, less "what should I do here" commentary...

Re: best rearend for the crown vic swap

Posted: January 28, 2012, 7:14 pm
by Gritsngumbo
unibody madness wrote:Thanks guys
Grits what specific years will fit ? do you have any pics?

I believe the years are 80-83. Just look for the F100 in the yards (as opposed to the F150). We initially thought they were scarce, but found they're not that hard to find. Think mine only cost $88 at the Pick-A-Part. They run anywhere from $200 to $400 in yards on the internet. I had heard about the F100's with the 5 on 4.5 bolt pattern, but didn't realize that they would be wide enough until Mustang Steve posted the info on his CV install (here's a link to his build pages on his website: http://www.mustangsteve.com/f100restoration.html . I'm probably going to buy Mustang disk brake brackets from him and source the other parts as I go along to spread the cost out. The one I got has a 2.75 ratio, so that will need to be changed, but I can probably use the one that's in the crew currently. If not, 9" pumpkins are plentiful and reasonably priced. Since my truck is going to be a cruiser and not a "Stroker" hot rod I'm thinking the 28 spline axles will be fine.
Now if I win the lottery a Mummert Stroker Y-block or one of the "new" 427 Y-Blocks will probably be in the picture, but then I can do the Moser internals :-)

Sorry, I don't have pics as my differential is still in Shreveport at Bluebolt's place (Brien). I'm still collecting parts for my crew.

Re: best rearend for the crown vic swap

Posted: January 29, 2012, 8:09 am
by SLICKCOLLECTOR
i think i am going to use the 73 f100 rear axle. 65 1/2 inch width. 2 inches narrower than the front. it has wide and tall brakes. probably not as good a disc brakes but good enough. i read 70% of the braking is done with the front brakes anyway. i am going to get the 31 spline axles drilled to the 4 1/2 inch bolt pattern and have an additional 2 inch wide tire width available on the rear. i got the DJM lowering bracket and shackles installed yesterday and will install the 73 axle as it is for now, then remove the axles after installation. the light weight f100's probably have 28 spline axles so if i installed the pumpkin in the 4 1/2 housing i would be looking for new axles. i already have the 73 rearend and it has the n case pumpkin and 31 spline axles, so it is probably the easiest to use what i already have. it is not easy to find someone to drill the axles here but i did find one shop. the only thing i still need to check is whether the 67 ltd i parted out this summer has the right size brake drums with the 4 1/2 inch bolt pattern. i found a lincoln versailles 9 inch rearend for sale but i read that the parts are hard to find so i am going to pass on that idea. he also wanted $350 for the rearend. it was on the kc craigslist a few weeks ago if anyone is interested. the next time i do this i will build a tamer rendition of this swap and opt for the 8.8 rearend and disc brakes but for now i want a hotrod. i guess it goes back to my youth and i couldn't afford the high dollar hot rods that some of the other guys in town had. thanks for the help.

jim oberg

Re: best rearend for the crown vic swap

Posted: January 29, 2012, 1:19 pm
by Gritsngumbo
Sounds like a plan Jim. Keep us posted on your progress. And don't forget pictures. :-)

Re: best rearend for the crown vic swap

Posted: February 1, 2012, 11:07 pm
by BobbyFord
This may help. Here's a swap thread from Fordification where one of the guys used a T-bird IRS and a CV front end...> http://www.fordification.com/forum/view ... =5&t=61554

Re: best rearend for the crown vic swap

Posted: February 2, 2012, 12:03 am
by fire truck
Gritsngumbo wrote:If I'm not mistaken, the early 90's CV rears are 5 in 5.5 so the axles would need to be redrilled to 5 on 4.5 for fronts and rears to match. That's why I'm going with the early 80's F100 diff. They are surprisingly easy to find.


You're mistaken, the CVs and LTD CVs had 5 on 4.5, That's what Randy used on his truck. They're more of them out there with LSDs though....

Re: best rearend for the crown vic swap

Posted: February 2, 2012, 1:38 pm
by longcabjohn
Another piece of probably useless information. The big ford cars (ltd) from 73 to 78, possibly later used 5 on 5, same as caprice and c10 trucks.



Johnny