I went with the Crown Vic front end as well just due to the fact it was cheaper than replacing my leafs and a disc brake kit. Just something to think about.



If all of your stock is in good shape, I would hav SID stretch my front axle and add some disc brakes, and get that baby low the old way!

 

I'am a street rodder and i have seen cars and truck a lot older than yours with rebuilt stock frontends driving over 100 mph with no problem. Go to the slat flats and you will see them going well over 100 mph. Just saying.

 

I drive my F-1 with a stock front end at 70-75 all the time (overdrive is great). Speed limit is 70 on most highways in MT. 85 would be pushing it though.
Just remember they drive like an old truck, not a modern car.

 

I've got a 56 panel with a 460 c6. I put in a fatman MII and Im happy with it. Still has the aerodynamics of a van when at 100+ mph. Going back, I would stay with a freshened stock suspension, disc brakes and add power steering. I say this because I drive it like a truck, not a hot rod. I would also go small block ford with AOD tranny. 500 hp is waaay overkill and 93 octane ain't cheap. Be realistic in how you'll really use the truck before doing ANY thing...good luck! ;+)

 

This pretty much sums it up.

 

isnt the crown vic to wide for the 48-52 frame up front?

im staying with the stock front end on my truck,im sure it can handle the old flathead in there.

 

Wow! what a lot of imaginative justifications for the writer's personal choice of suspensions without any factual basis.
Here are some facts:
The beam axle and leaf spring suspension was used by Ford well into the 60s when vehicles were traveling at speeds in excess of today's legal highway speeds without any regular loss of control due to this suspension.

Suspension type has no significant relationship to "handling a certain amount of HP", Early Funny cars and most Gasser class cars and even fuel dragsters used beam axles and in the Gasser class especially used parallel leaf springs with some HP in the 1K range and top speeds around 200 MPH in the quarter mile. Yes some were "squirrely", but that was due to other factors (short wheel base, raised center of gravity, track and tire traction) not the beam axle or leaf springs. There is a resurgence of 60s and 70s type Gassers in nostalgia drag racing events, and IFS is banned by rule!

If there is a problem with handling on the street with a beam axle, it's a mechanical problem with that particular vehicle (alignment, tires, worn parts).
I drove my beam axle equipped panel truck across the country, from NM to NC, much of the time at speeds above the posted limit without issue. When I purchased the truck I was already planning to do a IFS install until I actually drove it.

Transplanting an IFS from a donor can actually make the truck drive worse than the beam axle. Most IFS are designed for the average non performance oriented buyer to give a soft ride and be very forgiving if pushed beyond the design envelope (usually the vehicle will heavily understeer which is very forgiving under a sudden throttle lift or brake application. The suspension design is also heavily compromised to aid in the vehicle "packaging" or to use off the shelf components (glaring examples: CV and MII) and were installed in vehicles having much different chassis characteristics and weight distribution from one of our very flexible framed and extremely nose heavy trucks.
There are a limited number of vehicles where the suspension was designed without performance compromise and have weight characteristics similar to our trucks, The Jag unit and the Lexus sedan come to mind, but even those are reduced unless the matching rear suspension is used and the frame is fully boxed, large rigid K member or roll cage added. A few of the aftermarket IFS that ARE NOT based on the OEM MII geometry can be an improvement.

Bottom line: IMHO there is no legitimate compelling reason to install an IFS to replace the OEM axle and suspension if the stock suspension is in like new condition except to say you did.

 

Only on 4x4 pickups and larger trucks. Twin I-Beam from early '60's (coil spring IFS). I didn't hear anyone raving about their high-speed handling capabilities at the time. I've owned them and they are a different animal (better in most respects) than a BonusBuilt front suspension.

Gassers don't have to make emergency stops, dodge traffic, manage potholes, broken pavement, etc. They go in a reasonably straight line. They don't even have brakes on the front end (usually). Not an example applicable to driving on the street.

If the OP is looking to drive 85 occasionally out in the wide open spaces, mostly smooth straight roads, sure, he can get by with the stock suspension. Pray a deer doesn't jump out in front of him. For anything up to 65, I think they're fine, too. For someone who has touted the Jag IFS for years, I'm surprised to see you recommending the stock setup for situations clearly beyond its original design intent.

 

I thought I would add that drag link geometry is important.I have a straight axle in my 32 and drives fine.My friend's A roadster has a out of square/level drag link and has considerable bump steer on occasion.After a drop, level it out by shortening or lengthening your pitman arm.Huge difference in drive ability.

 

Opinions are like, well you know, opinions. The man ask for opinions, we gave them, now he can decide what he would like to do.

 

It was in his humble opinionthat should account for something.

 

Exactly what will happen to a parallel leaf sprung beam axle in an emergency stop? The springs would need to break, and I don't see that happening, Not seen many broken front springs (springs usually break from being overloaded, hard to overload the fronts.) My "opinions" are based on a great deal of studying suspension engineering, hard data and personal experience, not from seat of my pants or my imagination. Show me the data rather than SWAG. Last time I was at a drag strip, almost every car needed to make a near emergency stop at the end of the run. Gas class did and does require front brakes. cars without front brakes are required to have parachute(s). 4 foot wheel stands are a LOT harder on a suspension than any pothole that wasn't large enough to swallow an entire car.
I've seen a LOT more SUVs with IFS on their roofs than anything with a beam axle. Just having an IFS does NOT make the vehicle any safer in an emergency situation or in general driving.
I'm pretty sure Ford and/or Chrysler used a beam axle and parallel leafs on their vans well into the 60s.
Nearly every 18 wheeler on the road has a beam axle and leaf sprung front end.

 

Izzie just ask for some opinions on how he should proceeded. Why are some here getting thin-skinned because everyone else isn't jumping up and saying 'you were right, I was wrong". Give Izzie your input, and let him make his decision. No need to get defensive.

 

Nothing more than an exchange of opinions/ideas. I don't think this is either AX's or my first rodeo, but thanks for the concern....

 

But who handles the bull better, lol