Today I was giving the 503 (59 GMC) a good workout through the gears, revving a little higher than usual, and the exhaust pipe blew out of the manifold. Can any of you who are in the know tell me the connection method used? I haven't looked closely, but the top of the pipe looks straight (no donut). Does that mean that there was some sort of packing - or was there a lip that has rusted off?
Mine had a stock 3.0” necked down to a 2.5” muffler, totally un@cceptable. I took a large (3.5” I think) pipe, shoved it through the cast flange and with a ball pien hammer, formed the pipe fl@nge to fit the tapered flange(easy), so now I have a 3.5” exhaust pipe hooked to stock 4” Cummins muffler(kid reject) so it is quieter now. If you ever have the head off, it will take a .090” reduction.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
Thanks Ed, For your ideas on how to proceed. I'll have to do some measuring to see what I have. I'll start working on unbolting the flange, which is something that I worry a bit about. The engine has never been apart that I know of, but good to know about the shaving, if it ever needs to come apart. Nice truck you have.... that grill in chrome is super!
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
