Intake manifold gasket

My truck (2000 Blazer 88K miles) is in getting a new transmission and ABS work done right now ($3300). They called and said they pressure tested the cooling system and found a leak at the intake manifold gasket. $500 more dollars to repair. Couple question's. Could I have caused this by replacing the original radiator cap just a couple days before taking it in? I understand the original didn't seal well and by putting on a new one did I put the system under more pressure than it had been under and cause the gasket to fail? He said this was a common problem in these blazers too? If I wait a couple months and just watch the antifreeze level, am I going to hurt anything else or cause more problems? He also said that the 500 includes a cooling system flush. I thought I read on here that it wasn't a good idea to do a flush on these blazers if it never had one done before? Or did I just imagine that? My thoughts are they will dive into that problem, flush the system and find more problems.....Any advice appreciated. Thanks.

NO,You did not cause the intake manifold gasket leak by replacing the original radiator cap, FLUSHING THE COOLING SYSTEM is always a good idea on your blazer. I would NOT RECOMMEND waiting a couple months and just watching the antifreeze level, You can do alot of internal engine damage in that amount of time, should the gasket take a turn for the worst. What about doing the intake Gasket yourself? We have a great HowTo, on it...
Good Luck and keep us posted on your repair.

Blazers have a history of the uper manifold gasket failing in them. If you let it go you will end up having to replace the engine - ~$3000.00.
If you have some mechanical skill, you can elect to do it yourself (there is a how to posted in the how to section). Just make sure that you follow everyones advice, or you can cause more problems down the line. If you don't get it done you WILL end up spinning a bearing or causing worse problems, and it WILL cost you a new engine.
Look in the how to section, talk to a couple of the guys that have done it. This board is an excellent source for information and help.