Rlzegers

I'm building my 460 for towing an RV trailer around. I had kind of settled on using exhaust manifolds but after doing some research am really scared of the breakage issue with them and now considering headers. The way I look at it, I have 3 options. I can install new aftermarket exhaust manifolds with gaskets, install new exhaust manifolds without gaskets as some have suggested, or go to headers. The engine will be installed in my 1978 Ford PU F350, which came factory with the 400 so I'll be doing a swap to the 460. I see that Hedman carries headers they say "For engine swap" which are more expensive than the one designed to go into the 460 pickup applications. I'm not sure why the headers would be different from a swapped body as one that came originally came with a 460 unless there is an interference problem using the 400 cu frame stands with the engine swap engine mounts. My only experience with headers was years ago when I was a teenager and had a cheap set on my FE block and they were always loose and generally a lot of trouble. Long story short I'm looking for the best long-term solution given my situation. The engine will be subject to head temperatures I expect to be fairly high considering what I will be towing, especially in the mountains. If I understand correctly the manifold breakage is caused by uneven expansion from the cylinder head and the exhaust manifold during heating and cooling. What do you think?

Thank you,

Ron

photog101

I have a 1990 Class "A" with a 460 and I had the passenger side manifold warp on my unit. I removed the manifold and had it machined to true. Then I installed studs into the heads, renewed the manifold gasket and used nuts with thick Belleville washers. I now have over 10,000 miles on them and there is no problem. While I was at it, I did the same to the driver's side.

Two more things that I did is that when I shut down the engine, I give it a little cool down time before I shut off the engine. The other thing that I did was, while the manifolds were off, I sandblasted them and coated them with Never-seize. They look almost new today. This is an old trick that I used with aircraft engines. Let the manifolds cook after you do this in a well ventilated area, as they will stink until cooked. But no more rusty look in my wheel wells.

I did buy a set of Headers, but due to my Oshkosh frame, I would had to have moved all the brake lines, master cylinder, cruise control module and several electric looms to allow them to be cool during running with headers. Not worth the effort.

"Doc"