i just bought a 98 blazer 4 $300.00 and took it to the dealer and he tells me the coolant is all sludge. and lower intake is leaking. They want to charge big bucks for the repairs. any help to do this myself?

Reverse flushing a radiator is simple enough. Take er out and put the hose to it. Doing a lower manifold gasket is considerably more complex however. If you have a Haynes or Chilton read about the subject there, and look at the detailed thread that was posted just recently regarding the subject. Keep in mind your truck uses a different injection system than the trucks subject to that thread.

http://www.automotiveforums.com/vbulletin/showthread.php?t=485986&page=1&pp=15&highlight=lower+manifold

I got a 98 Blazer also. Do what Cailen said. Here is my post. It's not a how to do thread but the pictures will give you an idea of what your getting into.

http://www.automotiveforums.com/vbulletin/showthread.php?t=484806

If you have any questions on what I did, I try to help as much as I can.

Good luck