Just change out my exhaust manifold gaskets on my J10 with 360 and discovered a few things. First off the 2 center bolts were a pain in the &*% they were rusted down to the next size sort of and ended up rounding them off but picked up some Irwin stripped bolt remover sockets. (In case anybody is not familiar with them it is a socket with an internal lefthand tapered spiral that grips the rounded head of the bolt) These things are a life saver, within 30 seconds I had the bolts out. I also made things a little easier and drilled 1" holes through the inner fender in line with the rear 3 bolts and went in with a long extension to remove them, then just put some plastic hole plugs in the holes. (Did the same years ago for freeze plug installation). Anyhow, took notice these bolts which were original had a hole drilled in the threaded end about a 1/4" deep. Anybody know why? I tried getting replacements but nobody knew what I was talking about. My only guess is it has something to do with expansion and contraction. I ended up replacing them with grade 8 bolts. I checked to two 401's I have and discovered all the bolts are 3/8 diameter, where on the 360 the center bolts are 3/8 and the end bolts are 5/16. Hum! didn't know that. I also always have a problem getting the dunut gaskets between the manifold and pipe. Fel-Pros never held up that well but I had one from "ROL" which are really nice. (Got a great reinforcing ring compared to Fel-Pro.) I can't remember where I picked this up, anybody know who handles them? My local Advanced Auto use to but not no more. Heres a shot of those sockets.
