Headers

I ditched the old Doug Thorley headers because they wouldn’t work with my new motor. Too bad, because they were nicely made. I bought a set of Hooker Super Comp headers, part number 6111-HKR and have set about modifying them a bit. I ground out the tubes to match my heads’ exhaust ports, had the flange re-welded on the outside instead of just the inside, and am modifying the collectors.

The primaries on the left side are all within about .5″ of each other in length – impressive! On the right side, tubes 2-4 are close to each other, but a couple inches shorter than the left. Tube 1 is almost 5 inches longer than 2-4! It’s the best I can do, I guess. Hooker says they are “tuned” equal length primaries. I guess “equal” is relative. True equal length headers would cost a lot more. Tough to make.

To make up for the difference between left and right, I’m extending the collector .7″. The left-hand collector needs to be 18.2 past the ends of the primaries and the right hand needs to be 18.9. It’s not really possible to get very exact with it, because the ends of the primaries really vary (+- 1/8 or more). But, I’m getting real close.

Making the exhaust system is fun and challenging. I’m sore from lifting pipes into place over my head, fitting, removing, cutting pipe, lifting into place, etc. The headers are a real tight fit. The driver’s side one has to go in first. I have to lift the engine and move it over towards the passenger’s side in order for the pipes to clear the steering box and shock tower on the way in. Luckily I did install some Ron Morris engine mounts that allow for side to side and front to back adjustment. So, lift, move, put the header up and a couple bolts in, then shift the motor back to center and drop it. Then install the passenger’s side. It all has to be done multiple times in the fitting process.

headers - IMG_7271.JPG
headers - IMG_7271.JPG
headers - IMG_7272.JPG
headers - IMG_7272.JPG
I ground out the tubes to match the large exhaust ports of my AFR heads
I ground out the tubes to match the large exhaust ports of my AFR heads
I had my engine builder, Bob Gromm, TIG the flanges on the outside with phosphor bronze. This makes them strong, and seals up the thin areas left by my grinding
I had my engine builder, Bob Gromm, TIG the flanges on the outside with phosphor bronze. This makes them strong, and seals up the thin areas left by my grinding
This is the stock collector that comes with the Hooker Super Comp 6111-HKR. It's too short and too big for my application.
This is the stock collector that comes with the Hooker Super Comp 6111-HKR. It's too short and too big for my application.
I cut and deburred the collector and prepared it for welding
I cut and deburred the collector and prepared it for welding
This is the header next to my new collector pipe. The new pipe has a slightly smaller ID, which should be better for my torque curve.
This is the header next to my new collector pipe. The new pipe has a slightly smaller ID, which should be better for my torque curve.
I ground the edges of this down a bit because it's a thicker gauge than the old collector and I thought they should match up.
I ground the edges of this down a bit because it's a thicker gauge than the old collector and I thought they should match up.
tacking the new collector to the old. I cut off a piece of the reducer to use as a joining band
tacking the new collector to the old. I cut off a piece of the reducer to use as a joining band
headers - IMG_7432.JPG
headers - IMG_7432.JPG
new collectors with ball and cone adapters, tacked together
new collectors with ball and cone adapters, tacked together
headers - IMG_7439.JPG
headers - IMG_7439.JPG
headers - IMG_7440.JPG
headers - IMG_7440.JPG
headers - IMG_7441.JPG
headers - IMG_7441.JPG
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