I have a blown plenum gasket has anybody ever used RTV and kept the stock pan i thought about this because it is so flexible and would allow for the expanding and contracting between the pan and intake

 

I wouldn't use anything on it. Get a Felpro gasket and cut the bolts shorter or get new shorter bolts. Torque them a few times and use Loctite.

 

what year is your truck? I have an extra plate- which is attached to a one temperature bung keg.. $150..

the RTV won't work.. it won't remain flexible, but if that isn't enough, it will tear without structural integrity, and allow oil past anyway..

your options are a plate, or as Zman said.. the foolproof fix is the plate+ gasket..

the expense of this fix isn't the plate per say, it's the oil, the coolant, the gasket sets, o2 sensors, cat and opening that can of worms that makes everything else much easier to do such as water pump, timing chain, dizzy cap, rotor button wires and plugs, maybe even lifters... it's one of those "well, since I'm right here" things..