I have recently put a 460 in my 79 F-150 4x4. I have encountered a few snags and have gotten really good info from this site. My most recent snag is I am having trouble running the exhaust. I would like to use the stock manifolds I have. The reason for this is cost for a set of headers. I am dueling it out and allready have the mufflers and extension pipes. My touble is up at the manifolds. Can I buy a stock y pipe for a 2 weel drive and cut it ? Any advise would be greatly appreciated. Thanks, Jim

 

If your runing duals take the truck down to a QUALITY muffler shop an they can run them down each side seperatly on the trivers side it will have to dip down below the frome to clear the transfer case this is what I had done and I had them use 2.5 tubing I provided the Dynomax Super Turbo Mufflers and to get the exhaust done not counting the mufflers was a little under $175 from the manifolds and the mufflers turned down in front of the rear axle. You can see some of the exhaust in one of the pics in my galery.

 

Was that 460 from a car ?

The Right exhaust manifold is a bad choice to put in a truck.

Only a 460 Truck Exhaust manifold works well.

 

My truck has a 460 from a car, and as far as I can tell, the installer utilized the car manifolds. The exhaust is a definite cobble job, but most of the cobbling is on the drivers side pipe where it crosses over to the passenger side. What is different about the truck manifolds?

 

The truck manifolds are pointed down more as opposed to outward so the y pipe can fit inside the frame rail.

Kevin K.

 

I have to confirm that my truck has car manifolds. I see exactly what you're talking about kjkozak2. Whoever did the engine swap used a torch to remove a section of the frame to get the passenger side manifold to clear. Without being notched, the manifold points directly at the frame rail. I guess it was easier to notch the frame than to find a manifold. That's probably why there's a 3" suspension lift on the truck too, so they could use the car front sump oil pan.

 

Some of the hack work out there never ceses to amaze me...

 

Toolinaroundjpl,

I have said more times than I can recall exactly what mil1on says. Passenger Car Exhausts DO NOT WORK.

It req's a R/H Truck Exhaust Manifold, or settling for headers to put a 460 in 65-79 F Series. I'm probably one of few who actually prefer cast Iron OEM Manifolds for the adequate back pressure they do offer.

I'll spare you details, but suffice it to say I/m quicker at a faster speed with OEM cast iron exhahusts on my virtually box stock 385 than I was with headers I took off & sold. I also get better mpg w/ CI Exhaust. In reality my truck is a cruiser, not a racer.

One thing I can say for sure is stay with OEM style steel "shim" type gaskets with heat shield on them. According to FoMoCo, CI Exhaust manifolds rely on coolant flow in cyl heads as "sink" for excess heat build up. Use of composition, or combo composition/ steel gaskets MAY be cause of cracking in CI Exhaust Manifolds.

Fiber composition acts as an insulator, slowing or stopping heat transfer required to protect CI Exhaust mainfolds from an excess internal heat build up cracking them.

I read that in TSB a long, long, time ago, far, far, away when it was still popular to put 460s in Vans, Ambulances, Mini & Medium Motor homes and other app's where heat is an issue.

I've used same set of F Series manifolds on a few engines over the last 15, 18 years. They have not warped or cracked yet. I've yet to plane or reface them, They have over 1,000,000 miles on them at least.

As I exit, Dutherlerfordparts, when/ after you get your system straightened out, weld a repair plate over the missing section. The kick or up step at bottom of fire wall is the wrong place to cut a flange, top or bottom, off a frame rail ! It's a MAX STRESS area
as far as dynamic "loading" goes.

On running Duals. The OEM system used a "Y" or cross over to get around Auxiliary Fuel tank location. If you lack an Aux Fuel Tank fabricate L/H system from outlet @ manifold or header, all the way to the rear, or side exit, whatever. . . .

If you have Aux Tank, do what FoMoCo did, go around it.

Now I've seen 2 types of "Y" or crossover pipes. & 3 types of OEM Systems. One's single all the way after 2 into 1 @ "Y", then another is 1 in & 2 out of muffler all the way back, and 3rd is dual
"Y" with 2 into muffler and 2 out of muffler all the way back. What I dislike is how tailpipes are close together & side by side 'til they exit.
FBp.

 

I am definitely going to repair that before I do any serious work to the truck. I am planning a 350-400 horse 460 for the truck, and have no needful desire to twist the frame into a pretzel.