So this weekend I decided to upgrade the RH exhaust manifold on my Suburban ('91, 350, TBI) from the stock "3-piece" design to the more modern and effective "single piece" style. (I knew about one of the cracks but not about the one underneath the heat stove!) Other than having to break all three bolts on the exhaust pipe end (no biggie) no problems getting the old one off.
But when I installed the new one I must have gotten the 5th bolt from the front cross threaded and it broke off. I was re-using the old bolts. It went in smooth at first but I got to the point where it became too hard to torque and by then it was too late - required as much torque to back out as it did to go in. Good news is I have about 3/4" of threads sticking out - but what to do with them?? So far all I've tried is the two nut method - locking the first nut on with a second nut -- to no avail. Other ideas that don't require drilling down there or welding? I know it's probably a no-go, but what about leaving it as-is? Will that port not seal? The plan is to eventually upgrade the cylinder heads on that motor, but was hoping to not do that immediately! Any thoughts or tricks would be greatly appreciated, thanks.
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1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.