Had a search of the forum and couldn't find a post about the below, apologies if its been asked before....

I'm rebuilding an 89 F-150 from the ground up in my garage and was hoping to pick the brains of some people here.

a) The truck has a 302 hooked up to a 3 speed auto. I'm not sure what the diff ratio is but the truck does 3,000rpm at 100km/h (aka it was setup to tow). Can anyone recommend a diff ratio that works with the 3 speed that would have me cruising (sub 2K rpm) at highway speeds? I have no intention of towing with this vehicle.

b) As far an engines go, is the 302 windsor family consistent across the years?

My current EFI motor seems to have all manner of pollution controls etc hanging off it - EGR and AIR systems? (I'm still learning about these). Can these be removed without adversely affecting the engine? I want a real clean engine bay.

Also my engine is also has the speed density intake system which from what I read means I have to basically keep it stock to avoid running issues. I'm not after pure hp, but I plan on rebuilding it and it would be a shame not to bolt on a few aftermarket goodies while I'm at it. The current 302 is a little weak especially if I make the diff taller.

In terms of wiring etc, is the EFI 302 from my F150 very similar to say a 302 out of an AU falcon?

Appreciate any assistance.

Adam

 

a) Almost certainly a 4.30 rear axle ratio. (If you have 30/31" tires... if you have smaller tires, probably a 4.10)
Changing your rear axle ratio that dramatically will probably make your truck pretty gutless. If you have a 4.30 at the moment, a 3.08 rear end would put you at around 2200rpms and about as low as I would go.

b) Yes and no. The short block for the most part is pretty consistent (i.e. block/pistons/rods/crank etc.). Heads vary a bit over the years/what vehicle it was fitted to, fuel systems, intake/exhaust manifolds etc. varied a lot over the years.

I believe the emission systems can be removed (but check in the Windsor forum). Easiest way is to convert the engine from speed density - which I think you can find out how to do so in the Windsor forum.

 

Appreciate the insight mate.

I have been digesting a lot on info off USA forums, but its reassuring to hear from a fellow Aussie as I know the information is 100% relevant.

Couple more questions I had:

Do you know what diff my 89 F150 came out with? My manual has about 4 listed but I'm not 100% sure what I have.

Also, just curious if you know ballpark figure for getting ratio's changed in a diff? I am a fair way off looking at the diff yet, so I have not made any inquiries.

 

When you say what diff, do you mean what ratio? Most likely a 3.55

As for $$$ for changing the ratio's... depends. Your best bet will be to buy the parts from the states (8.8 rear ends are a dime a dozen there) and fit them yourself.
If you aren't comfortable fitting gears and shimming them, you could just buy a whole axle from the states and fit it and sell the one you have got, anyone setting up a street/strip Mustang will be interested in buying the ratios you have at the moment.

 

Thanks mate, it's hard to know whats been done to the truck as a lot of it is not original.

I think it has a 9 inch diff going by internet resources that detail the differences. No ID tags on diff. If the diff is leaking (dripping) oil out the yoke that connects to driveshaft, would that just be an oil seal that I can replace?

Also wondering if anyone can tell me how truck suspension is lifted at the front (like what components are modified)? This truck has a couple extra leaf springs and couple blocks under the leaf springs jacking up the rear to what I'm guessing is a 2 inch lift but I'm not sure what has been done to the front.

Last question, is a power steering box difficult to rebuild? I can get rebuild kits from the states for $60 and I thought I might as well do it if its doable at home in the garage?

Appreciate your time guys

Adam

 

I would be surprised if it is a 9"... possible, but they stopped being fitted to trucks in the early 80's.
The oil leak will just be the seal.

Front suspension is usually lifted by longer springs or by placing a spacer where the spring mounts (for coil springs).

The 2" block at the rear is standard.
No idea on the power steering box - its distinctly possible its out of a falcon of similar vintage, and not the box from the states, I haven't had a great deal to do with effies of your vintage.

 

I would be surprised if it is a 9"... possible, but they stopped being fitted to trucks in the early 80's.
The oil leak will just be the seal.

Front suspension is usually lifted by longer springs or by placing a spacer where the spring mounts (for coil springs).

The 2" block at the rear is standard.
No idea on the power steering box - its distinctly possible its out of a falcon of similar vintage, and not the box from the states, I haven't had a great deal to do with effies of your vintage.

 

My God - I haven't seen this signature in Donkeys years

How have you been, Lad?

~a 650 CFM willl light it up like a mule going up a ladder

 

If it has a rear cover (bolts on the rear of the diff) then it's probably an 8.8, if the bolts are on the front then it's a 9in and the whole center is removable.

Lift Kit

I'm assuming being a F150 it has a TTB front diff. Coil springs, not leaf springs. Either way the above link has lift kits.

Look at my build thread for pictures of the performance lift kit installed in a 1986 F100 4x4.

Basically new pivot boxes, drop boxes, radius arms and coils.

 

Depends on PO's. My 84 chassis came with an 8.8, yet my 86 has a 9in.

Mind you I think I'd rather have the 9in, easier to get rebuilds for in Australia and replacement parts appear to be cheaper.

 

Thanks mate.

Yeah I was reading your build thread. I am at a similar stage (down to chasis after bare metalling entire truck, respraying chasis with rust proofing, then rebuild from there), but I am not straying far from stock as I don't have the skillsets / experience that you obviously do.

Yeah, I guessed it was a 9 inch because the back of the diff is fixed, no bolts. Plus it has the non stock gearing so it had likely been replaced.

On a side note, how the heck do I change the diff fluid? I can see what I assume is a drain bolt on the bottom but no bolt / place to fill it up?

 

On my diff.



The fill point is the plug where the red dot is.

To drain it you have to undo all the center bolts. Pain in the neck really and should have a separate drain hole.

Some have a drain where the lowest retaining bolt is.


And I need a new gasket.

 

Actually so far what I've done has all been basically bolt in. The only item I've had to fabricate is the extra support for the engine chassis plate on the left hand side. The sheet metal brackets (fuel pump and filters) are not necessary but just make it easier.

The lift kit only needed some holes (eight) drilled for the drop boxes all the rest was bolt in.

Fuel and brake hard lines are easy to make. If you have the originals then it's just a matter of duplicating them. I've moved the line that runs to the rear from the engine bay so had to work this out from scratch but the rest are stock.

Brake flex lines need to be approved so just need to have a sample that a brake place can make them up for you.

When it comes to remounting the tray I'll have to get into more fabrication as I want it mounted well but will be some cutting and welding only.

 

Thanks for the picture. I had not noticed that fill plug on mine, I'll have another look tonight.

On the picture, mine has a minor leak (drip) from the yoke connecting to the driveshaft...to replace the seal is it just a case of unbolting the connection to the driveshaft, unbolting those 5 bolts near the yoke and is it hiding around there somewhere? Trying to work out whether I need special puller tools or anything to get in there?

For brake and fuel lines I just planned on replacing them all with new stainless lines (although the brakes are already stainless I think) and some braided brake lines to connect to the discs / drums.

How much was it to have the chasis sandblasted? I planned on stripping it all myself.

 

Found the fill plug (under some dirt and mud), it's actually set into the case and looks like it fits a socket drive. It's in the exact same spot as yours though.