I'm at my wits end trying to install replacement headers on my '83 after the old ones cracked (they were late style). The 1/4 header just doesn't want to go in no matter what I do.

Of the 4 studs/nuts that secure it, only 3 will line up at any given time. The 4th one is always off by a mm or so. I've tried removing studs and having the other nuts very loose or very tight and everywhere in the middle. It just moves the issue to a different stud location. Do I need to wallow out a hole or something? I've spent hours on this and can't get all 4 studs lined up.

I've even tried using a scissor jack between a section of the frame and the #4 primary (to move the whole header forward) and it doesn't do much at all, the studs would break before I got the spacing I need.

 

Any chance the new headers are warped? That would be my best guess. It doesn't solve your problem tho...

 

I assume you have not mounted the lower triangular flanges, if not I'd unbolt it there.
--
The solution is to drill out the hole (s) 1 size bigger.

 

They tend to be tight - you have to get the very tips of the studs in the holes and wiggle them into place rather than slide on easy.

Drilling out does make it a ton easier though.

 

Last time I saw something like this was about 50 years ago reinstalling headers on a 390 Mustang. With the 390 engine in there so tight you couldn't see so it was all done by feel. With 7 of 8 bolts started (no small feat) my friend spent 3 days trying to start the last header bolt with lots of people dropping by to give it a try. Somehow with prying and twisting I finally got it started much to his relief. General consensuses among the gearheads was the warped flange was caused by the weight of the unsupported mufflers hanging off the collectors.

 

I would slot the outer flange holes with a dremel to accommodate the thermal expansion of the head vs the plumbing. aluminum grows. drilling might not leave enough clamping area.

I believe the weight of the exhaust contributes to head gasket failures on some Subaru models as well as lack of enough grounds and high pH in the coolant.

 

Thanks guys. I'll throw some more time at it, and then if that doesn't work, oval the hole a little. I had no idea it was this tight of a fit, I never had an issue installing headers before. Maybe it's warped, although this is a cast header and they're pretty stout.

 

I know that on early SB chevy's one has to use a tool to compress/expand the cast iron header to get it fit the head. Since it looks like it needs to be compressed a bit..perhaps a large c-clamp? Gently applied? Just a thought..

 

I had a set of header like that for years. Every time I installed them, the holes would be off like that. I took and M8 bolt and cut it so that it was just a hair shorter than the distance between the flanges. Then I'd thread a nut down over the threads so the end of the bolt was just proud of the nut. With one flange bolted in place, I'd put the bolt/but between the flanges and loosen the nut until the nut/bolt was wedged snugly between the flanges. Then I'd use two wrenches to further loosen the nut, which would force the flanges apart until the hole lined up. It was a pain but it worked until I finally found a less warped set of headers.

 

I've put on and taken off many headers on these cars and have never had an issue like that. They usually slide on like butter. My bet is that something is bent or warped. Are both holes shifted to one side on just that particular port or just one? Did the other port on that Y line up correctly?

 

For sure, I went through a pile of replacements to find an unwarped one -- many of them were warped to some extent. These were 951 headers but same idea...

 

...maybe the issue is from those ****ty stud/copper nut kits

 

What do you have against these kits?

 

Last year I did a head gasket job on a 944S2.
The owner wanted to switch to the SS studs and copper nuts, the same ones odonnell is using.
Since there are more studs on a 16v head the owner bought 2 such kits.

All the studs had poorly-machined allen holes at the end that would round out with hand force from a normal allen wrench. The copper nuts were garbage - I know they deform to lock onto the stud, but these ones deform immediately and make it a REAL PITA to thread them down all the way. I had to way over-exert to get them threaded on - the force required made me think more than once that I was going to strip out either the hole in the cylinder head, or the nut itself.

After a few HOURS of work they were all finally in place and locked down maybe it was bad batches but...never again will I install those no matter how much someone will pay me to do it.

Stock steel on steel is just fine for me, thank you very much.

 

Interesting. I too use them. I've had my headers on & off a few times since installing them. In fact, I have another set I intend to use for my intake manifold the next time it comes off.