If you have broken studs the best repair technique is to cut them off flush with the head and drill them out with a purpose-built drill guide purchased from a chap that goes by the screen name A Quiet Boom over on the Pelicanparts bb. Should you buy a guide from him let me know as the he doesn't supply the right sized pilot. I made my own and I'm sure he would make one for you if given the proper dimensions.
As for heat exchangers, they should be easily sourced over here in the U.S.
Check Ebay for them as well as the various breakers we have here.
I would encourage you to drive another car with headers as they do transform the car. You can keep the stock stuff on the shelf (as I have done) for later installation when required.

 

Thanks for that.What I want to do is cut the heat exchanger pipes 1.5" from the exhaust flange on the cylinder head.The 3 'allen' nuts are well worn and tight.The other 3 nuts are smaller than they should be because of rust.With the heat exchanger out of the way Ill be able to get heat in about the bolts and nuts and release them all.The broken ones will be taken care of by my 'magician'.He's the man who can weld a tin can to the *** of a cat!!

 

Duncan, if I recall correctly, the heat exchangers are the same part left and right - it's just the connecting pipe that bolts on to each one that is different.

 

Last time I looked the heat exchangers are the same on the left & right, the RH exhaust outlet is extended across to the J pipe with a seperate cross-over pipe; it's only the n/a 964 that has handed exhangers because the LH one is built with an integral merge and cross-over pipe. That should help with your search!

 

Here's a pair on Ebay U.S: http://cgi.ebay.com/ebaymotors/Porsc...item3352ac5bdc