I too had a plastic intercooler on an 05 that regularly saw 35+ lbs of boost, but like everything else, when yours will fail is the million dollar question. Do you have any mods done to your truck that increase fueling(ez,tst,ect. ), If you do, they do boost fooling at the same time and you will run higher boost and will tell you your on borrowed time. But I have seen a few factory units separate on stock boost and I have seen a few intercoolers survive 35+ lbs of boost like mine. Its really your call, you could wait till you have a problem or start to include it as part of your future upgrades. Also, if your truck is under warranty which I assume it is, then if or when it happens the dealer will replace it with an aluminum one since DC no longer uses the IC w/ plastic end tanks.
Richard