1963 Cadillac convert 390 motor broken exhaust flange studs motor pull

[Roberts 63]

Engine pull 1963 any need to knows. I have broken studs on the exhaust manifold heat riser studs and on the other side flange. The engine bolts on the main manifold are really rusty so I feel I better pull the motor out to replace the studs in perhaps two take the manifold off and start fresh any input would be appreciated

[The Tassie Devil(le)]

Robert,

You have a second email from the Moderators that still requires your attention.

Bruce.

[russ austin]

Just pull the heads with the exh manifolds attached.

[Roberts 63]

Is removing broken exhaust manifold heat riser studs on extremely rusted manifolds a reality

[Jason Edge]

I've had my local machine shop remove a dozen or so broken exhaust manifold to exhaust pipe flange studs over the last 2 decades. Assuming the bolt is broken off flush, they create a hex head for it by placing a nut over the top of the broken bolt, filling the nut center with weld, heating everything red hot and backing to bolt shank out.  I've seen them do it time and time again... about 10 minutes or less and don't recall them every not being able to get one out. If there is enough of the bolt shank sticking out I will usually remove them myself by heading everything up gripping with a monkey wrench or large vice grips.  You can also take new cobalt hard metal drill bit and drill out the center and and retap. Since our Machine shop recently shut down I removed one in this manner myself a couple months back. I have never gotten into welding ... something I definitely need to take on now with my local machine shop shut down for good.

As far as removing the exhaust manifold, everyone isn't ready to just crack open the engine by removing the head. If the head needs to come off anyway that is an easy way to remove.... just eat your Wheaties that morning... I just removed a pair like that last month and you will need to dead lift head and manifold up and out of the engine bay. Not to bad for a young buck, but will make a 56 year old do a little grunt. If head comes off be sure to install with new head gasket and make sure rocker arm assembly and everything is reinstalled in exact same orientation so oil get's up to the shafter and rockers.

You can also get the exhaust manifolds off with engine and heads in the car with a bit of effort but you want to use a 6 pt 14 mm socket (slightly smaller than than 9/16") and make sure you have a snug fit. You might need to remove the large 3/4" motor mount nut (easy to get to by lifting one corner of front and using a long extension, U joint, and socket) and lift up engine a bit and/or remove the inner fender shield for better access.  If you go at these bolts haphazard with a 12 pt 9/16" socket you may think you have entered a strip club after a few rounded bolt head.  I haven't used anything but 14mm sockets & wrenches on these bolts for at least the last 2 decades.

One final bit of advance is to let a machine shop (if you can find one), plane the matting surface to the engine flat. They tend to warp a bit with age and can cause exhaust leaks.  Also, might as well clean'er up a bit and spray some of the good Bill Hirsch or other exhaust paint on it... or any other exterior treatment you are into.