while i was putting the thermostat housing back on i noticed that the top of the bolt connected to the intake manifold is totally missing the threads so i can't bolt it all away on. is there another way to fix this other than replacing the manifold?

 

tap it

 

I keep my stuff a long time and work on everything I can do myself. I don't think GM ever puts anti-seize on any steel bolt going into an aluminum manifold. If you can get the bolts out, and the threads are good, put studs in the manifold for the thermostat, distributor hold down, carb, brackets, etc. If you break a bolt off you'll have to drill it, and use an easy out to get it out. If the threads in the manifold are damaged you can use a tap to take it to the next larger bolt size. You can carefully drill the hole in the thermostat housing out to match the new bolt size and keep your manifold. If you continue to use bolts, you gotto use anti-seize (or formagasket if the bolt is going into a place where water or oil might try to come up by the threads)