Hi guys.

If I understand correctly I need the entire fresh air intake system off of a 7.5 litre. What year range am I searching for? My intention is to get the most efficient "free breather!" Moreover, I am removing the smog pump including all of the plumbing and ultimately install dual 3" exhaust. My goal is not horsepower but an efficient, smooth running engine.

All input is always welcome!

Many thanks!!!

Mark

 

Dual 3" on a 5 slow? Hopefully that was a typo and you meant dual 2" because even a single 3" is too big and will kill low rpm torque.

And no you don't want the complete intake setup from a 460 the tubes are shaped differently, you want all the plumbing from a newer 5.0 truck with the snorkle(part between the air box and rad support) from an I6 or 460 truck... and it doesn't matter which one they're identical.

 

Thanks Conanski!

There is a boneyard about 45 minutes from me with a lot of Fords. Now I understand what I need to do. Perhaps the newer (94, 95, 96) the better.
I do have a single 3" from a gutted cat into a small glasspack and I had them dump it just behind the rear axle. I plead ignorance as I was informed by the "exhaust man" that it would improve mpg.

Down the road would you run dual 2" exhaust with perhaps some headers or am I asking too much from such a small block?

I sincerely appreciate all of the input.

Thanks!

Mark

P.S. This is a California truck and I stated previously that I want to remove the smog pump and all of the associated plumbing as the charcoal cannister has a hole in it and in my view the engine is "pushing the pump" when I can simply remove it and procure a shorter serpentine belt and remove a lot of plumbing. Currently, I receive 18-19 mpg on cruise control at about 65 but there is definitely some speedometer inaccuracy.

Is there a way to either replace a gear or calibrate the speedo?

 

the snorkles and tubes (from the I6 and 460) are more or less the "same" as far as being "free breathers" the tubes are honestly over kill for our trucks so its good enough, the better breather would be the tube from the I6/460 engine which would put the tube intake end behind the grill (technicially behind head lamp on driver) but that will give a more free flow of air, where as the snorkel is some what restrictive due to its location...

 

Any 88 or newer 5.0 or 5.8 truck will have the fender mounted airbox and correct intake tubes for your application but a 95 and newer will have extra stuff on it you don't need(mass air) so your window is 88-94.

The restrictive part of the stock exhaust includes the manifolds and stock Y-pipe, if you replace those with headers and aftermarket cat you would see some gains but you're gonna need CARB spec parts so your choices are more limited.

The motor in your truck makes peak HP at 3800rpm so it's not really stressing the accessories that much, you can certainly remove some stuff and "clean up" the engine bay a little but it won't gain you any noticable power unless the pump is seizing and putting extra drag on the motor.

On that truck to recalibrate the speedo you need to replace the driven gear on the trans end of the speedo cable. Do you have over/under sized tire on it?

 

Just the scoop right?
Here ya go

 

The 4.9/7.5 tube is the way to go. Stick with a good quality OE style filter.

Excessively large exhaust will not help fuel economy at all, and will make the truck sluggish. For dual exhaust, I would go with 2.25 on a 5.0. If going with single, 3 inch is alright but bigger than needed for a stock engine.

 

No, just the stock 235/75/R15.