Hey all,
Stabbed the 460 and c6 tonight (nice to be on the 'put back together' side of things). Installed the Hedman HD headers and am very happy with how they fit overall although I don't envy the exhaust guy.
One of the tubes on the passengers side was touching the top frame rail (where the frame juts out to a point) so I ground off and filed smooth a little over an 1/8. Now at the closest it's 1/16 away from the frame.

Since the fenders are off and the lifting plate is still on the intake, I am going to grind a little more but was wondering what distance I should aim for?
Side question - the 460 pulls up and away from the passenger side right?

 

New motor mounts may help that clearance issue. Also, I have had to loosen the head bolts a little bit on the head, and then take a long pipe and stick up in the header collector and pull down with all my weight to tweak the headers down for clearance.

You say you do not envy the exhaust guy. If it's like the long tubes I have installed, I would also not envy the guy who has to service the automatic transmission, replace the starter, etc. You are going to also want to tell the exhaust guy to as soon as possible get the exhaust up high where it's supposed to be. If he runs it at the same height down low where it is now, you will be able to see it from a side view of the truck and it looks bad with all that hanging down. It's bad enough hanging down up front where it can get caught on stumps, rocks, etc. I have run them, but I am not a fan of long tube headers on these trucks.

 

From personal experience, I would keep the headers at least a quarter mile away from my truck...

 

@Franklin2 It actually has new mounts on it now so however much distance I give it now will be the most it will ever have. Although I am still thinking that the engine lifts on the passenger side (when running). Sitting under the truck last night I was trying to picture how the exhaust would be run because like you said, I don't want it hanging down low to where you can see it although some may be unavoidable. No problem of course if the driver side could cross over behind the bellhousing but since the header collector terminates back near the trans pan, that's not doable. I haven't got the tcase on yet and am afraid that will be an immovable wall for the drivers side routing. I figure worst case I will have to put the logs back on but I'll cross that bridge when I have to. That service guy will be me so at least I know who to blame! I have a powermaster micro starter on it which I could install without loosening the headers although it did take me a while to find a way to wiggle it up there. Regarding the transmission I was a little concerned at first with the cooler line clearance but it turned out all right. The deeper trans pan I have does reduce the clearance even more on the drivers side. I am going to stop typing out things I noticed because it makes it a little harder to keep telling myself I like them. They do look good though


@kr98664 Touche, although unless I hear otherwise I am going to take your numerical value but just change the units I figure a 1/4 inch at the closest point will be enough space and due to how the top frame rail flares toward the motor at that point, I can take an 1/8 off with no concerns.

 

What I did on one of my header installs on a 80-up Ford was put a 90 degree elbow directly on each collector, and ran each side under the frame* pass side and driver's side. As soon as it cleared beyond the outside of the frame I put another elbow pointing to the rear and upward at a 45 degree angle. I then put another 45 degree elbow on this to level it out, and then I had a cat convertor and a muffler on each side up high on the outside of the frame. After all that I had a 45 degree pointing down and outward, and the exhaust exited on both sides of the truck in front of the rear tires just beyond the body. All you could see was some pipe hanging down up front, you could not see the cat convertors or the mufflers.

I sort of knew it would not pass inspection when I first put it together. My first version didn't have any cats in it. When I took it in sure enough he would not pass it. But he said if I put a cat in each side he would which surprised me. So that's what I did, they were something like $60 each for a universal type you clamp in like a muffler.

Another version I always thought would work well would be to get rid of the side tank, and just have the rear fuel tank. The switching stuff the factory had usually goes bad anyway and if you need all that fuel capacity they make 38 gallon tanks for the rear location. Getting rid of the side tank would open up the driver's side for exhaust, though if you did this I would re-route the fuel lines for the rear tank to the outside of the frame. They run inside the driver's side frame rail now, and with exhaust running along there also it would not be good and have a tendency to vapor lock, been there done that.

*P.S. I just remembered I had to take a large hammer and oval the pipe a little bit to get a little more clearance between the elbow and the bottom of the frame. Very minor flattening.

 

Ended up running to the jy this morning so checked out an installed transfer case to picture it some more and I don't really know how the exhaust can get by that without either going outside the frame like you mentioned or crossing over under the transmission pan (doesn't sound like a good idea at all). I thought about ditching the mid ship tank but I like having the two tanks (may revisit that if the valve goes out). Even with that tank gone I am still not sure how it would get past the tcase. I'll go ahead and improve the clearance for now and address the drivers side routing later.

Who knows, maybe I'll just put downturn tips right off the collectors and run open headers (I kid)

 

Hi , the torque reaction for the block is for the drivers side to lift up , if you have watched any engine masters on YouTube they did a header test and dented in some header pipes , there would be very little power loss .for one pipe . cheers.

 

I get why and the reason for rerouting to the outside frame but seriously...
Why would you ever want to reroute the fuel lines to outside the frame rails?
That is potentially a serious safety issue if you should ever get T-boned.
food for thought is all I'm contributing, not attempting to start an argument, just another point of view.

 

You have to do something different with the fuel lines. You cannot run the fuel line open on the inside of the frame rail, with a hot exhaust pipe running in the same area, it just won't work. Either move it to the outside or make some sort of full length shield to deflect the heat away.

 

I know, like I said I understand the reasoning on moving it. I just don't believe the outside frame is a good spot either.

 

Installed the transmission crossmember, transfer case and overdrive this afternoon so aside from some transmission and tcase linkage I have a pretty good idea of what the exhaust guy will be working with.

I am thinking it will be possible to cross over the transmission crossmember beside the front driveshaft, loop under the tcase-to-transmission connection and then run duals like normal.
Due to how close it is to the transmission pan already I figure I will be wrapping it from the collector until it meets the passenger side.

 

What OD unit is that?
It looks like it has GV (gear vender?) on the left side for the front drive shaft so does it do OD in 4x4 mode?
If so did not know GV made them for 4x4 to be used in 4x4.
Dave ----

 

Yeah, it's a gear vendors unit. An older model I bought with a truck in Gary's neighborhood not long ago.

It has a 4x4 lockout switch to prevent it from being engaged in 4wd so the different ratios don't leave you in a lurch (literally).

I haven't seen one that works in 4wd - which if it did, could be a really good selling point for some regions.

 

OK I did not think they made one to work in 4x4.
I guess that part to the left is the other half of the transfer case cover and how the GV unit "bolts up".

On autos from what I have seen you unbolt the tail shaft housing and bolt up an adaptor then the OD unit.
I figured the 4x4 units bolted up the same way guess not.

Cant wait to hear how the GV unit works in your truck. What gear ratios does the truck have?
Dave ----

 

You got it. I see how that might look odd but yes, it doesn't actually change the workings of the tcase but rather removes the nose and replaces it with a flat spot that their adapter bolts too. It's actually a rather clever and easy to install setup. I need to figure out the driveshaft part now. Wouldn't be hard to measure except the carrier bearing is throwing me a little so need to do some research on that.

The truck has 3.55 gears so better than if 4.10 but I decided to get one installed because the truck was going to be down for awhile anyways and the price was right.

I didn't do a build thread, although I debate about it often, just because I am not great at keeping up with stuff like that but I'll definitely do a recap thread at some point and will include how the gvod is working.