I have to take off the upper and lower plenum for some work (done this before) and I have a set of head gaskets too. How many people recommend changing the studs from the top, by removing the cylinder head. Is it a lot of extra work. any risks etc. Also , where can I get the manifold machined (pepboys ? etc)

 

Totally unnecessary to remove the cylinder head for exhaust stud replacement.

Yes, sure it's tight with them on, especially if you must drill out a rear one. But it is doable.

Any competent machine shop should be able to true the manifolds for you. Glad you realize this is an important step in the repair process.

 

 

Are you saying that I can do it from the top with the heads on ??? Or are you saying that I should go in from the bottom (tough for me as I am a big guy that wont fit under the car)

 

you'll pretty much need to do it from the bottom of the car if you leave the heads on it..

If you can't fit under the car, then I recommend pulling the head.
once you have the manifolds off, it's only another couple hours to get the head off and back on.

 

Can I reach them from the top if I take off the rear valve cover ( but not the head)? Or will the rear support still be in the way.

 

Valve cover removal will not gain you much if any access to the studs.

You will probably just have to start removing parts that are in your way until you can get to the studs. If you get to a point where you cannot see/reach/access them, remove more stuff until you can.

 

the big issue is room to work.
in order to get the rear manifold off, you need to pull the y pipe (of course), and then the rear engine mount and bracket. to do that, you have to drop the crossmember. once you get all of that down, you have to lower the engine down a few inches to get room to get a drill in there. by the time you do that, the top of the head is only a few inches from the firewall. very difficult to work on things when you can't see what you're doing once you get your hands in there.



you can pull the heads by just removing the y pipe form the manifold and then pull the head & manifold off at the same time.

BUT.. you have to pull the timing belt and covers off the other side so you still have a couple hours of work.

so there's hassles with doing it either way.... but if said person is physically not able to get into the space under/behind the engine, then he'll have to take the head off and do it out of the car.