So ive posred before about fixing the heat riser tube to the manifold cuz its not connected. Its a new tube its not broken off it jus necer got connected and I see why. Ive tried the pop rivit techneqe and tht jus wouldnt work for me. So is there any other possible ideas if bot would it be better to seal the hole in the manifold?
What exactly is the problem? Is the hole in the exhaust manifold too large or too small? If it is too small, drill it out to fit the tube. If it is too large, then try finding some bushings to make it fit, or braze a larger piece of tubing on the end of the original tube.
You can drill it out, no problem. Just do not go too big. The reason it is too small is probably because there is an old piece of rusted tube in there. Just drill slow, take your time, going up one size at a time. The heat riser hole does not port directly into the exhaust within the manifold. If I remember correctly, the hole goes straight down out the bottom of the manifold. Maybe someone can verify that just to be sure.
Drill out the hole to 1/8 pipe thread tap it use a compression fitting on the tube with threads on the end screw into new threaded hole
A 1/8" NPT tap is .009" shy of 3/8". This will be a large hole. It would be easier to file the tube down to fit the manifold hole