Alright, I am ready to concede. I have tried fenderwell headers, to loud, to low hanging, to hot so I tried inside the frame, to close to the steering shaft, to tight to run pipe around tcase. Besides they will prabably leak at some point or need constant retightening. I should have listened to y'all and stayed with the manifolds:mad: I have finally come to my senses and decided to bolt back on a pair of good ol' fashoin AMC V8 manifolds. Of course the emissions stuff is long gone. I need some advice as to how to close the smog bosses in the manifolds. I have looked for a pipe plug to fit but the bosses are a real wierd size. I measured the threads at .55". what the hell kind of size is that!?!?! :confused: . If I have to use the factory hollow bolts in the bosses how do you recommend blocking them off? Weld the hole in the bottom shut? Weld the 2 holes just below the head of the bolt shut? Any Ideas? I would really like to find some pipe plugs that would fit but the hole seems to be a straight .55" not tapered. If I find a plug that fits sorta can I cross thread it into the hole then run a bead of weld around it to seal it up. I know that you shouldnt weld to cast but is it okay if it doesnt bear a load only seals a leak? Thanks in advance for any help. And to all those considering headers.......... Just Say :flipoff2: :flipoff2: No!!

I think a spark plug will work for that. looks pretty bad though. I think knocked the porcelin out and welded then shut. pain in the butt just retap for pipe plug

I had the same problem with the manifold emmission bosses. Go to napa or something and get some small freeze plugs and drive them in on a work bench. Still holding after 500 miles, it's not pretty but it works pretty well.

Never ran headers on mine but have heard enough to stay away from them :D Only way I'd try them is if I made them myself (or had them custom made).

Regarding the smog ports, I just used bolts (had to trim the length, the shortest length I could find in that size was still too long) with copper washers. I thought about a plug but didn't see any way to seal the threads. I'm hoping the copper washers will deform enough to seal (I cleaned up the mating surface). I don't recall what size that thread is though, sorry. I also can't confirm if the copper washer trick works because I haven't had the engine running long enough to tell :( Sounds unattractive and you're right... it isn't much to look at and cutting all 7 bolts was a PITA. Previously what I did was cut the smog tubes off right at the tube portion that the bolts go thru, then welded the hole shut on that tube. Again not very pretty, but it's an option and would probably look and seal better than what I have. This time I didn't want to cut up the smog rails so I tried a different approach. I wanted to be able to go back to the smog setup if I ever have to. If the copper washers fail I'll find some of those crush washers like it used originally. Ideally I'd like to find some older manifolds without the smog ports if they exist. Been checking every time I'm at the boneyard and haven't found any yet :(

Tack weld a nut, sized, slightly larger than the threads of the manifold bosses, over over the holes. Then use the nut as a guide and run a tap through nut, into the manifold. Run a bolt with a brass crush washer, and plenty of Lock Tight into the manifold, through the bolt and tighten securely, then put a continuous weld around the nut. I used this method to seal up a water galley boss, on an old in board sailbot engine, many years ago, and it held for over 10 years, of being pressurized, with salt water.

The theory behind doing it this way, is that the treads of the nut, having much better thread contact than the tapped over threads in the manifold, will pull the new bolt up through the threads of the manifold, crushing some of the threads and sealing as they do. Your continuous weld around the bolt afterwards, will probably not have to actualy perform any of the sealing duties, it just locks it into place. You will probably not even be able to remove the bolt without cutting away the welds on the nut.

to plug the holes: first, i broke off all of the smog-fittings with hopes that one would come out. i was wrong. i then drilled them all out with a 9/16" drill bit and tapped them 3/8" NPT. i think there is enough meat left after breaking the fittings off to drill them out 7/16" and use a 1/4 NPT tap. i just happened to have the 9/16" drill and a 3/8" tap that friday night. i then installed Hex socket pipe plugs (McMaster # 44605K233, $0.12 each) to fill in the holes. it really wasn't too bad and looks really good finished. it was well worth the time and $0.84 for 7 plugs. matt

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