Big Block Chevy Header Install - 1967 Chevelle
Facebook lost its collective mind when I installed a big block in my Chevelle without laying the headers in the frame beforehand. I had an ace up my sleeve. I was using the new Mid-Length Headers from Hedman. No tricky twists and turns coaxing these bad boys down into place, I thought.
Generally, I try to start with the hardest task at hand first. This allows for surprises and a gentle climb up the learning curve. Mostly though, it’s because I’m stubborn. I set off installing these headers very apprehensively. You see, they are coated with a newly offered ceramic coating that’s extremely fragile and stains easily until heat cycled. I offered up myself as a guinea pig to try this experimental coating that I was considering offering on a select assortment of our headers. Why? Because white VHT on headers looks awesome. Except, removing headers to repaint them every year is an excessively cruel thing to do to yourself.
Often, white headers start with a case of freckles and deteriorate to a nasty orange-ish grey. The hope with this done as a ceramic coating is to allow for the removal of contaminates and oil before they bake in and ruin the finish. They can be cleaned with soap and water or a light solvent. It was recommended by the coating company that these be handled with gloves during the install and treated gingerly until they had heat cycled a few times. That would be the true test and help add to the finish’s longevity.
Donning the finest blue nitrile gloves that money can buy, I set off on my quest to bring a little of the late-sixties to life in my garage with white headers.
Not much to report on the passenger’s side. It dropped right in from the top without even having to loosen the starter. I was in trouble. That meant that the driver’s side was going to be a nightmare. I originally thought that it looked like the left header would drop into place from the top.
It turns out I was sort of right. Except I think some crucial instructions must’ve gotten lost somewhere along the way. Who here knew that the steering shaft on most big block headers snakes between the primary tubes? A show of hands. You smug bastards. You didn’t say a word about it either.
Okay, who here also knew that the steering shaft on a ’67 Chevelle is one piece from the rag joint to the nut at the steering wheel? Again, you guys let me down. How did I not know this? This turned into a long night in the garage. Part of a Saturday and most of one Sunday.
As it turned out, GM adopted a collapsible steering shaft that had telescoping DD shaft and tubing that, upon impact, would slide into one-another. This joint is held together with an injected nylon. Much like later model GM truck u-joints. You heat the area where the nylon resides with a propane torch. After a little while, these little worms of melted plastic ooze from the holes where there were shot into the joint at the factory. Once the nylon is removed, the two shafts can be separated.
After I was able to get the large, flange end of the rag joint and part of DD shaft that’s welded to it separated, it became much clearer what needed to happen. The steering column itself was set to the side to be installed on the slip-shaft later. The short section of shaft attached to the rag joint flange was held in reserve as well, while the header was fished down into place from the top. At that point, it looked like it was a 50/50 of being possible from the top as it was the bottom.
But wait, there’s more. As I twisted and turned that cluster of tubes every way I could think, it became evident that there was no way it would clear the upper control arm mount and bolts. I ended up also removing the two UCA mount bolts and lifting the wheel and lower assembly to take the load off them. This allowed me to raise the upper arm of the frame mount and rotate it forward out of the way. Only then was I able to get the header down into place and bolt it up. Then the lower shaft could be fished up between the pipes and re-bolted at the rag joint.
In the end, I scraped the hell out of the paint on the cylinder head around the exhaust ports in a couple of places. I also gouged the paint on the frame rail by the upper control arm. To add insult to injury, I also scraped the coating on the header in a few places that aren’t really visible to anyone but me. I’ll see them every time I change the oil.
One other modification that ended up being required was the replacement of the clamp on the lower steering column. Originally, these are equipped with a pinch clamp like a tie-rod end has. As it turned out, the header tube was too close to this clamp to allow full rotation of the steering shaft, which is sort of important. I replaced the clamp with a slick little 1” collar clamp. Naturally, and as usual, I had to tweak that a little as well. It wouldn’t clamp as securely as it needed to in order to keep all the guts in the lower column. I slight removal of material on the butted surface with a 1/16” cutoff wheel snugged it up well. It just clears the header tube when everything is assembled. I may turn a small amount of material off before final assembly takes place.
This article ended up longer than most, which is indicative of the project. Would I do it again? Sure, now that I know the secrets and tricks, I’d gladly scrape and ding somebody else’s brand new parts for them. Until next time, here’s hoping it’s a smoother learning curve.
