Magnum 360 Headers

[RRChris]

I have a 360 Magnum in my 71 Satellite Sebring. It currently has headers on it (not sure what type, but looking at web pictures definitely not TTI or Doug's, look more like Flowtech, Patriot, or Hooker).
Found today that the pitman arm is hitting one of the tubes on full lock.
Also, despite the Magnum Swap site saying that LA headers bolt right up to a Magnum there is a slight mismatch to the ports.
Is there a fix to the pitman arm hitting the tube (other then denting the tube further than it already is)? It has new engine mounts. Is it possible the engine is slightly off centre?
If I went for new headers to fix the interference problem, can LA headers be made with Magnum exhaust flanges to fix the port mismatch? Is this something that TTI, Doug's , Hooker, etc will do?
If I went for new I would probably consider shorty style headers to eliminate the tightness around the steering area. There are shorty headers made for Magnum motors, would they work?
Anyone with any experience on this?

 

[rumblefish360]

Limited experience here. But....

The LA heads have that odd shape and the Magnum heads are much more squared off. As far as I know, nobody makes a true Magnum head exhaust port header. The mismatch will always be there to some degree. It is something NOT to worry about. Exhaust kind of doesn’t care unlike an intake charge.

I would not bother with shorty headers. A better header that will fit your car really well is ether the TTI or the Hooker “Super Comp” headers (not the regular Competition units) which are a straight 1-3/4. There fit is excellent. Both the headers are near equal in expense. I have 2 sets of each. I find the Hooker easier to install.

Header hitting the steering linkages?
Dent the tube.
The engine should be slightly off center. That is normal and correct.

 

[rumblefish360]

Hooker Super Comp pictures in a ‘79 B body.
Plenty of room around the P/S box and steering shaft, Familiar design on the passenger side, just a larger tube. Very good ground clearance. With these headers, you do not have to take apart the front steering linkage is to install or remove them.

 

[YY1]

I believe there are Magnum specific port headers available.

You would look for 90's to early 2000's truck applications.

I can't speak to whether the bends would work in cars, though.
Trucks don't have torsion bars to deal with.

 

[rumblefish360]

I believe there are Magnum specific port headers available.

You would look for 90's to early 2000's truck applications.

I can't speak to whether the bends would work in cars, though.
Trucks don't have torsion bars to deal with.

Now that is something I didn’t consider. I was just thinking of old cars. If one had welding talent.......

 

[YY1]

I really wish the Magnum manifolds didn't have that big sag right on top of, if not actually touching the power steering gear adjustment tower in a B body.

I would LOVE to run those.

They flow good and sound good.

 

[RRChris]

Hooker Super Comp pictures in a ‘79 B body.
Plenty of room around the P/S box and steering shaft, Familiar design on the passenger side, just a larger tube. Very good ground clearance. With these headers, you do not have to take apart the front steering linkage is to install or remove them.
View attachment 972895 View attachment 972896 View attachment 972897 View attachment 972898

Wow. Tight fit. #1 cylinder looks very close to PS hose fitting. Doesn’t hit? Maybe best answer for me in short term is to provide a little more relief in the tube on mine. Will be putting in another steering box in the next few months, don’t want side loads to impact sector shaft.

 

[RRChris]

I really wish the Magnum manifolds didn't have that big sag right on top of, if not actually touching the power steering gear adjustment tower in a B body.

I would LOVE to run those.

They flow good and sound good.

Don’t know about the sound - don’t get to see any in Oz. But I agree for the Magnum engine their original cast iron manifolds would be ideal - but the PS is the problem.

 

[RRChris]

I believe there are Magnum specific port headers available.

You would look for 90's to early 2000's truck applications.

I can't speak to whether the bends would work in cars, though.
Trucks don't have torsion bars to deal with.

Agree. That’s why I thought the shorties would be better - they stop above the torsion bars. However, not sure if Magnum shorties would be too wide for a B Body engine bay - again the PS box. If using LA shorties for the drivers side does it matter if the exit is centre or rear of the manifold?

 

[MoparLeo]

The Satellite engine compartment would fit the 426 Hemi from the factory. The "Magnum" 5.9 is just a next generation LA engine with improved port and combustion chamber design. Internal mods. Externally dimension identical to any 318/340/360 . Shorties have very little exhaust improvement over good factory manifolds. Is this a recent swap or just purchased the car ? These things would have been noticed at the time of the engine install and not have shown up later. Fix the lock stops. Is the contact minor or major ?

 

[RRChris]

The Satellite engine compartment would fit the 426 Hemi from the factory. The "Magnum" 5.9 is just a next generation LA engine with improved port and combustion chamber design. Internal mods. Externally dimension identical to any 318/340/360 . Shorties have very little exhaust improvement over good factory manifolds. Is this a recent swap or just purchased the car ? These things would have been noticed at the time of the engine install and not have shown up later. Fix the lock stops. Is the contact minor or major ?

I appreciate that the Magnum is a re-jigged LA and externally there is no dimensional difference, and that given our cars had 426 Hemis in them then there should be heaps of room. However, modern vehicles that had Magnums in them originally didn't have the same power steering set-up necessarily and probably different steering linkage arrangement. Therefore headers made for Magnums may not fit our vehicles. My concern on a Magnum shorty header is if the tubes for cylinders 1 and 3 come out too far from the head, before turning down, they risk hitting the PS box. I was hoping someone might have had experience with this??
I also get that shorties are not a great improvement on stock manifolds, but when I can't get stock Magnum manifolds to fit then shorties may be an option. I am not after a race engine. I just want a system that seals and doesn't interfere.
I bought the car with these headers and have been slowly working through issues on the car. Unfortunately the previous owner(s) didn't identify the interference, or chose to live with it. I have had knocks in the front end to which I have re-bushed the whole front end and new shocks all around (ball joints are tight). Despite this fixing a lot of the issues a couple of knocks persist, one that actually appears to be bad door hinges on right side (you helped me on that one in another post), and the other I have now discovered is the pitman arm hitting the header tube near full lock. I actually found it by seeing the headers / engine move sideways up to a couple of mm when the steering was turned towards full left. Fairly sizeable dent in the tube already.

Maybe another option is to find a pair of LA cast iron manifolds here locally and make those work?
Otherwise, it is working with better headers for LA engines in the future.
You mentioned fix the lock stops - what lock stops?

 

[MoparLeo]

When you said that shorties might be too wide for the engine bay, I just pointed to the widest engine offered in that engine bay. OK. The point was That the "Magnum" engine is dimensionally the same externally, therefore there is no "Magnum" header. It is just a 360. The "Magnum" was only available as a truck application engine until the Gen III 5.7 Hemi replaced it in 2003. They make 360 headers for 1962-1979 B-body. Same header whether a 360 or if you prefer the newer name 5.9 . Cylinder head type doesn't matter as long is it was factory so 360, 5.9 Magnum, same headers. The problem is probably the header application. Unless you can find a part number or tag to identify, the previous guy did not necessarily put the right parts on. Some go strictly for the price or deal and don't always get the correct part. I put a 5.9 Magnum factory crate motor in my 73 Challenger many years ago with "340" TTI headers. No fit issues at all. Same header. A lock stop is where the spindle makes contact on full steering wheel lock. It has to hit somewhere. The contact point is the "stop". Depending on the model over the years there have been many types of stops used some adjustable.

 

[RRChris]

When you said that shorties might be too wide for the engine bay, I just pointed to the widest engine offered in that engine bay. OK. The point was That the "Magnum" engine is dimensionally the same externally, therefore there is no "Magnum" header. It is just a 360. The "Magnum" was only available as a truck application engine until the Gen III 5.7 Hemi replaced it in 2003. They make 360 headers for 1962-1979 B-body. Same header whether a 360 or if you prefer the newer name 5.9 . Cylinder head type doesn't matter as long is it was factory so 360, 5.9 Magnum, same headers. The problem is probably the header application. Unless you can find a part number or tag to identify, the previous guy did not necessarily put the right parts on. Some go strictly for the price or deal and don't always get the correct part. I put a 5.9 Magnum factory crate motor in my 73 Challenger many years ago with "340" TTI headers. No fit issues at all. Same header. A lock stop is where the spindle makes contact on full steering wheel lock. It has to hit somewhere. The contact point is the "stop". Depending on the model over the years there have been many types of stops used some adjustable.

Agree with the above. When I was talking shorty header part of the discussion was about those specifically made for the trucks with Magnums through to 2003, and therefore my question as to suitability for B Bodies. Sorry if I lost that in all the discussion. The only difference on the Magnum is a slight difference in exhaust ports, otherwise as you say the same.
However, point taken with application. It seems that B Body small block LA headers are used on Magnum successfully. Understanding there are recognised brands that have no fit issues. I hear great things about the TTI's - just price is a killer. But I also agree about using the correct parts. It's not always about price - can cost you more in the long term.
Unfortunately, while this car has had many things done right to it in the past, there are a few things I have to shake my head at - but that's another story.
I thought the steering lock stop was internal on the steering box and not adjustable at all? Isn't the stop the end of travel for the worm unit?
I appreciate your discussion!!! Thanks.

 

[rumblefish360]

Wow. Tight fit. #1 cylinder looks very close to PS hose fitting. Doesn’t hit? Maybe best answer for me in short term is to provide a little more relief in the tube on mine. Will be putting in another steering box in the next few months, don’t want side loads to impact sector shaft.

No, it only looks close. I’ll try for another who later this evening after work. The f your engine mounts are shot, it’ll hit.

 

[RRChris]

No, it only looks close. I’ll try for another who later this evening after work. The f your engine mounts are shot, it’ll hit.

Fair call on the engine mounts. Mine are a couple of years old. I checked engine location measurements this week against that of TTI recommendations and everything comes up OK. When I change the steering box in a few months time I will have a good look at what is going on then. Not sure if new pitman arm will have a different "curve" to it. Or with the headers out it may be prudent to change the profile of the tube it is hitting.
Thanks again for everyones input.