Hey guys, just asking a quick question, I'm looking at a set of 20" 2007 f150 king ranch rims and I'm driving a set of 17" 2009 f150 xlt do you guys think they should fit??

 

Yes

 

Probably they will fit, but there are some 04-08 rims that will not fit the 09 up due to interference with the calipers. Not because of diameter, but because of width. For sure, FX4 wheels from 04-08 will not fit as the caliper would hit the spokes of the wheel. The 04 XLT 17" rims will fit. They miss the spokes by about 1/64". I know as that is what I use for my winter tires. If they would let you try to put one on the front of your vehicle just to make sure it will clear is probably the best way to check.
Also make sure you either get new TPMS sensors or move your current ones to the new rims. The old 07 sensors do not work with the 09 up.