Dean, The stripped thread in the head can be repaired with a heli-coil or similar
insert. Here's a video showing the process. For the manifold studs, a machine
shop can fix you up. They will cut off the old studs and drill and tap the
manifold. Might need to use thread inserts like on the head. Depending on
available equipment you may be able to do these repairs yourself.

 

Well, the first thing I would check is to see if there are deeper threads in the stripped hole that are good yet. In other words, could a longer bolt of the same size be made to grip? Because from some of the other things you have mentioned about the car, it is possible someone used bolts that are not as long as they could be. See if you can get a good closeup pic (macro setting) of the damaged hole so we can see how bad it is.

Regarding the headpipe studs, post a pic so we can see if some really are welded in, but if they are just frozen/siezed, usually you can soak the threads with a penetrating oil like PB Blaster or Kroil or SeaFoam Deep Creep, then get two nuts and use one as a jam nut so you can back the stud out, and if needed use a propane torch to put some heat into the manifold at each stud as you try to back them out.

It is possible that you may need new manifolds, but sometimes getting the studs out is easier than you think it will be, once you know the tricks.

 

Heli-coil is going to be your best bet, but once you get that problem solved I would use studs instead of bolts for your manifolds or headers, especially if you have aluminum heads. Just to make sure it dosent happen again.

 

I'm probably one that doesn't care for Heli-Coil. I prefer to tap for oversize Bolt or Stud but then you can use a replacement Threaded Steel Cylinder which is an end all solution , especially in Aluminum: where, I've used, numerous times with great success, on Ali-Motorcycle Spark Plug Threads.

 

I still have the original 327 engine complete with the 1200lb cast iron intake manifold...that damn thing weighs a lot...and the original heads. I think I'm headed the heli coil route as this seems to be easiest method...plus this gave me an excuse to purchase a BITCHIN tap & die set.

I'm going to let the manifold studs soak in PB Blaster overnight and hope for the best in the morning. If they won't budge I'll try and find a machine shop in Oklahoma City somewhere that will drill them out for me. I'm betting that won't be cheap so I may be in the market for a new set of manifolds in the near future.

 

"plus this gave me an excuse to purchase a BITCHIN tap & die set. "

Dean, Heli-coils require a special tap. You can buy a Heli-coil kit in the correct
size that includes the tap. Here's a link to probably the most expensive place
you could buy from.
http://www.mcmaster.com/#helicoils/=hb4rd8

 

Hey, any excuse to buy a really bitchin' tap and die set will do. I'm personally tired of all the cheap sets I seem to end up with.

 

Well, the first thing I would check is to see if there are deeper threads in the stripped hole that are good yet. In other words, could a longer bolt of the same size be made to grip?

Yep
Im also one who is not a fan of heli coils...drill out and retap a size slightly larger....
The studs in the base of my cast manifolds I have done this...new studs then tack miged them in place on the back side.
I also have a water neck stud that is redrilled and taped over size....means I have to drill a little out of the water neck....