I agree with cat, definitely need a 3/4 axle back there at least. Lots of torque coming out of a 460. I think even with 250 springs in the rear you will need traction bars. I get pretty bad axle hop sometimes in my 250

 

There was a bunch of discussion on axles early in the thread. The consensus is that he'll need to upgrade there.

A 10.25" full-floater would be good, but heavy which will hurt ride and handling, and have 8 lugs which won't match his front (without changes there).

A 10.25" semi-float MIGHT be able to be drilled for 5 on 5 1/2 (Dana 60 semi-floats can). Also probably not quite the weight penalty.

A 9" could easily be built to handle his power without being too heavy, and it has 5 lugs. But it won't have a VSS so he'll need to work that out.

I don't know what it would take (or if it's possible) to build an 8.8" to handle the power. But that would definitely be worth looking into to see if it's an option.

 

bob, being in the industry , I can tell you 1 there is limited better braking systems available for these trucks , especially in the 5 x 5.5 this is a problem when guys want to run original wheels on the 30-50's fords , its cheaper when they update to their mustang 2 and other chassis kits to go 5x4.5 . 2 leaf springs, any stock spring is going to be an issue, for instance on my 96 f150 4x4 , had a rancho kit with the blocks and add a leaf, I went to 4 inch lift f250 spring that is rearched and have no traction problems what so ever . 3 the front end, will it hold , sure , but the ball joints are already a problem on these trucks and now your adding oh 200-300 lbs + or - to the nose. the 3/4 over 8500 and the f350 use a better bigger joint . which will better deal with the weight change . you figure the 4.9 in the truck weighs 400ish pounds , that 460 iron headed is 550-650 depending on accessories and transmission. the frame would have no issues whatsoever .

 

The summer has come and I'm out of school. Now I have more time to dedicate to this project. At the moment, I'm searching for a good 460 engine with accessories. It seems that buying a parts truck with the engine already in it would be cheaper in the long run. I've been able to find f250/f350's with the 460 for around $700~$1000, same body style as mine.

Before I drop anything in to the truck, I need to hunt down the rivet(s) that are/is making the popping and solve the popping brake calipers.

As for the rear axle, I might go with the 9in rear end.

 

Not sure the engine plans but comparing an aluminum head BBF vs all iron sbf, the difference isn't as great as most think.

There's folks putting a lot of power to the 8.8s.

Something to think about.

 

When I get the engine. I'm going to keep it stock for a period of time to see how the truck's components react to the new transplant. I will fix or upgrade as things break or wear out. After I get the supporting mods in check, I will stroke the engine to 545ci with a street-able mild cam and tune.

 

I don't know the stock axle will take the torque, since it has a 3.08 ratio.

 

I'm going to chime in here with a comment or two.

A bare 460 weighs about 135 lbs more than a bare 351. That's no trouble for a set of replacement HD F150 springs to accommodate. That 460 isn't as heavy as some people believe and the 351 is heavier than most people would suspect. 640 lbs vs. 510 lbs.

That 8.8 axle is tougher than you would think. There are too many Fox-body Mustangs using that same axle design behind high horsepower motors and they live. The key to axle longevity is to avoid axle hop like the plague. Axle hop loads/unloads the gears on each hop, placing very high loading on the teeth. Common failures are the ring and pinion and the pinion support bearings. Keep in mind that a truck is light in the tail and kind of hard to hook up, too.

If this were my budget build, I would do a 4-bar with leaf spring floaters to control axle hop. For safety, I would find someone that could do a 9" axle bearing conversion so the axles are retained by plates and I would have a set of Summers or equivalent axles made to accommodate this conversion. You would still have the tone ring for your VSS, too.

If you really wanted a 9" diff, Brea Auto Electric makes a reluctor setup that would give an input for the VSS. Worth looking into. I think my build would go this way. Still using the 4-bar and leaf floater.

For braking, I would just go with EBC high performance pads/shoes and slotted rotors.

Now that all of this has been said, I might scrounge a F150 to take with me to Indiana when I retire. The thought of a BBF-powered Effie kinda gets the juices flowing . . .

 

Okay cool. That means I can focus more on front end and finding an suitable engine.