I've been planning my next project for quite some time now and I've about gotten all my questions answered.

Here's the plan. I have a 57 f100 that I spent last summer sand blasting and getting ready for paint. I'm going to start off this summer reblasting a few areas and hopefully will be able to get the whole body in paint. Then I move on to the mechanical side of things. Here's where I still have some unanswered questions.

My plan has been to pick up a used P71 Crown Vic at the state auction (probably 06') and use it as a donor car. I would drive the car around until the body is done, just to make sure that if there are any issues with the car I can fix them before I've taken the whole thing apart. Then, when I was ready for it I was going to park the Crow Vic and begin a front and rear suspension swap, as well as an engine swap with the Crown Vic's 4.6L.

Now, here's where my questions come in. Regarding the suspension swap, I've read a lot of threads about people doing this same thing, but to the next generation of trucks which are a wider up front and in the back.

From what I've found the 57 should have a track width front and rear of 61.25 inches. Does anyone know if the Crown Vic's front suspension with a track width of 62.8 inches will be too wide for the truck?

I know it's technically wider, but I'm just not sure how much room I have to play with up there so if anyone has done this, or attempted to do this please let me know.

The next question is regarding the rear end. I know the Crown Vic's rear is way wider than my current 9inch is, and the Crown Vic is only an 8.8. Would I be better off keeping my current diff and just spending some money on it or trying to widen my rear with either wider fenders, or some sort of bed modification?

I really want the disk breaks in the rear and the Crown Vic already has them. Would it be possible to graft them to the old rear end if i can't use the whole thing?

Those are my main questions right now. I'm just trying to make sure that I don't buy my donor car and find out that I'm out of luck.

Any information or opinions on the matter would be greatly appreciated.

hotrod

 

Why not just put a disc brake kit on your 9" Personally I think the 9" is a much better rear end than the 8.8 and you already have it.

 

The only problem with that is the cost. With the Crown Vic I get all of that stuff for a few thousand dollars. I can't really afford to spend hundreds on a brake kit in addition to the donor car.

That's why I would be much more willing to even modify my 9 inch to accept the 8.8's brakes if that was at all doable. I haven't tried that before and I don't have the car yet to really see if it even looked possible.

 

You can use the Crown Vic suspension and axles if you want to do the adapting, as the width difference is not that much. You can match things up by carefully selecting wheels with enough offset to keep the tires under the fenders as long as you do not go crazy on tire width.

 

I was planning on keeping the stock cop wheels, at least for a while and i believe they have about as much offset as you can get so i should have a leg up there.

3413, Are you refering to just the front or the front and rear?

I was pretty sure the front would work, but be tight, but the rear i'm not too sure about. Oh, if i matters it's a stepside bed.

 

Here's what you do...whatever it takes to put that 8.8 in that truck and I'll PM you my address where you can leave that old 9 inch...

Just kidding.

I vote for keeping the 9". Why do you think you need the rear discs? Are you going to go road racing with it? You could probably find the donor parts (front end, 4.6, tranny, and power booster) for way less than the cost of that donor vehicle and save a bunch of hassle by keeping the 9 inch. I know I'm a lot less picky when it comes to brakes than some, but I only ever owned one vehicle that I ever put any real miles on that had rear discs and they didn't even work...and I didn't even know it! One day I was washing the wheels and noticed that the rear rotors were completely rusted...It always stopped fine for me. I have a '55 Fairlane and this '60 F100, and they both stop alright, but it could be better. Anything I've owned with power brakes has been great with discs up front and drums in the rear.

 

I guess the only real reason I feel like i should have disks in the back is because I'm going to be adding them upfront and it just makes sense to have them all around. That and I know i would have to spend money on the rear brakes regardless of what i do so i figured why not go the more modern route. If I were to keep the 9 inch and just rebuild it i guess i could find the disks off something later model that would fit, or better drum brakes at the very least.

Everything I've been reading suggests that the 9 inch is the better rear, it would have just been so easy if i didn't have to worry about anything and could just bold the cop diff right up. It would also eliminate the cost of a limited slip since i think the crown vics have one factory.

I still feel like it will be as cheap to buy the whole car since they're less than 3 grand and i wouldn't have to worry about not having the right parts or anything like that.

Keep the info coming, if anyone has added disks to a non disk rearend (specifically a 9inch) I would love some information or pictures (or both)

 

It is actually more rare to have discs all the way around, than front discs and rear drums. If it were me, I'd leave the rear drums exactly the way they are, get the front end set up the way you want, find a power booster and master cylinder for disc/drums and be done with it. That would be cheap, easy, and be on par with just about 80% of the vehicles on the road. All you'd need is the engine, tranny, front clip, booster and master (plus all the little stuff that ends up costing a lot) and when you're done, you'll have a modern power plant and updated braking. The fronts do most of the work anyway.

FWIW, I don't mind the way my '60 F100 stops right now, (manual drums all the way around) but I am planning to do a 4 wheel power drum setup with a dual master. I think the power booster will make it 10 times better. Even when I put a dual manual master (non power) in my '55 Fairlane, it stopped a lot better than the 50 year old stock master. I just don't want to see you spend a bunch of money that you don't need to spend.

 

A lot depends on what you are going for. If you are going to swap in the CV front suspension and keep the rear as is, you have a wheel bolt pattern mismatch, but adaptors can fix that with the attendant track increase. Now, on the rear - would you stay with leaf spring or swap in the whole CV rear suspension setup? Choice #2 makes you keep the CV axle, but for choice #1 it would be simple enough to modify the CV axle to fit the existing leaf springs. For the drivetrain, the CV rear axle will be strong enough.

As you may be transplanting the whole drivetrain (and the ECU that is necessary for the engine and trans) you may also be able to keep the anti lock brakes and traction control if your donor car has that. It all depends how deep you want to get into it.

 

3413:
That's more like what i was planning. I wanted to basically take the whole mechanical portion of the Crown Vic and put it under my truck. I know it will be tough, but i'm ready for that. the only thing that i'm worried about is the rearend giving me trouble and that causing a ripple effect. I think it will be much easier to get everything working properly if the only real difference in the setup is the body.

Has anyone tried widening rear fenders? I would assume it's a real pain but it might be cheaper than the fiberglass wider fenders I can get. If not widening the rear fenders I was considering widening the whole bed a little by basically cutting it in two and splicing in a few inches but i don't want the truck to look odd.

 

I think you will be pretty tight on rear clearance with the C-Vic rear but it will probably fit.
The rear track of the C-Vic is about 2" wider than the front.
The measurements I have show a rear track of 65 3/4 and overall width of 73 1/4.
I am not sure if the 73 1/4 is to the edge of the tread or to the widest part of the sidewall.

My 1959 F-100 has 31-10.50-15's on the rear with the stock 9" and they fit just fine. They measure 69 1/2 to the edge of the tread and 71 1/2 to the sidewall. The box sets above the tires enough to eliminate any tire clearance but even if dropped it would have about an inch on each side.
With a 73 1/4 overall width and dropped it would probably be very near to touching the fender lip.

I hope some of this helps.

I think the thing to do is go with an earlier C-Vic rear which is about 4" narrower than the newer ones. This will give you the discs you want as well as keeping the front and rear wheels the same bolt pattern and back set.

A '98 or so C-Vic rear should be pretty cheap if you look around a little.

 

One thing that hasn't been brought up...Why are they auctioning off a 2006 Crown Vic? I would be sure to check that out very closely...if it doesn't have 300,000 miles on it, then there might be something else. If it was a police car, all the cops I see in my travels start the car at the beginning of their shift and shut it off at the end, so there's a lot of idling- even when they worked a construction traffic detail and knew they weren't driving anywhere for 8 hours.
I know my company gets rid of fleet vehicles every so often, and it seems like a deal- a four year old vehicle for $3000, but it's a four year old vehicle with 200k on the odometer that was kept up by a cost conscious fleet manager and driven by someone that has an "it ain't my name on the title" attitude. Just make sure you check it out closely.

 

PA auctions them off just over 100K miles it seems like. I'll be sure to check it out thoroughly but I've done a fair bit of research and they're a good buy for the most part.

Even if the swap doesn't go through I'm fine with just having the Crown Vic as my daily driver to replace my very well broken Jetta so short of getting a lemon i'm pretty safe.

 

I will be flamed for this opinion, but having been building hot rods and restoring trucks for a lot of years, and now at the age that I am quitting such work except for my own stuff, I feel that what you want to do would ruin the value of an old truck.

Why do we like old trucks? Because they are different, and take us back to the day when they were new. Why then would be ruin the effect by making the old truck new?

Leave the suspension and the frame alone, if you want to use the late engine and drivetrain, wire up the FI and computer, OK, but leave the suspension alone. The drum brakes on the truck are Bendix self energized and stop extremely well. These trucks do not need disc brakes, but you can put discs on the beam axle.

Regards,

Alan

 

In my opinion, which I know is worthless, We will never use these old trucks as they were built to be used. If so, why settle for a harsh ride from an outdated suspension that was intended to haul heavy loads over rough terrain? My truck will occasionally be called upon to haul more than just the passengers who'll fit in the cab, but for all of those empty bed cruises, I'd like a smoother ride.
Several folks reccomended mounting the CV rear on the original springs, why? You will still have a hard ride in the rear. I mounted my rear on 88 Ford Ranger leaf springs along with a 88 Bronco II sway bar for a ride to match the Lincoln IFS out front.