Hesitation cha cha cha

Ok, here's one for you guys. My dads 93 Bravada 4.3L Vortec is idling rough, and seems to stumble a little cruising. Started up very hard, had to floor the peddle, but I checked the spark plugs, and all three on the driver side were fuel fouled, not to badly, but enough to make it hard to start. Anyway, all three on driver side had unburnt fuel smell, all three on passenger side were fine. firing great. I'm thinking this is do to a leaking gasket between the intake manifold and the CPI cover. I've never run across three bad spark plug wires on one side of a motor, and there doesn't seem to be any sounds comming from the motor that would indicate some mechanical problem. Anyone got any ideas on this??
Its got me stumped and got me two nasty cuts on my hand trying to get to the stupid spark plugs.

TO'd in seattle

Your gonna love this: go back and pull all the spark-plugs. pick up a compression tester at autozone. Go to the local library and copy the engine troubleshooting pages out of Chiltons for your mdl yr or just pick up the Haynes manual at...autozone (no I don't work there). Run a compression test of all the cylinders and compare. If the left back is lower than the right then you have a compression leak somewhere. Also check your coolant for any signs of oil contamination, also check for coolant in the oil. This will rule out a head gasket leak.
This should get you started. If everything checks out, replace the sparkplug wires and plugs, rotor & rotor cap and you should be fine.

Don't start it again without changing your oil. The fuel lines inside the intake manifold are cracked, spraying gasoline inside, fouling the plugs and deluting the oil. I fixed mine after having the same symptoms as did another bunch of Bravada owners at another Bravada site(now dead). There have been some that continued to drive waitin' for a better day to start work and the deluted oil destroyed their bearings and crankshaft $$$$.
Check it out before anything else.
Sorry, that's just the way it is.

Regarding the spark plug replacement, you can get to them easier by accessing them through the inner fenders, through the rubber flap. I bought an extension with a 5/8 socket and wobbler combination tool for easy work at my favorite auto parts chain store.

Oh, I forgot, check for trouble codes.

Well, as hard as it was to believe when chris first suggested it, he was right. Thanks chris. Was a $500 dollar fix cause I replaced the injector while I was at it, but the fuel lines in the manifold were the problem. There was two inches of fuel sitting in low portions of the intake manifold, being sucked into the cylinders on the driver side. Amazing.

Sorry 'bout the trouble but you're ok now.
If the passenger side plugs were gassed it would've been a leaky fuel pressure regulator on your CPI...I did my fuel lines first then a coupla months later the CPI went bad. Now I hear the regulator can be replaced....figures.
I'm having what feels like a lean condition on my '92 but I haven't got the Trouble Code 44 yet...probably get to take the fuel tank down to replace the fuel pump :>/