Narrowed axle, safe wheel to frame distance?

I'm about to narrow my axle for my truck, it's a wishbone four link, just wondering how close is to close? I'm trying to stuff fours under the truck and I don't want to fumble this up, also would overnarrowing be ok then correcting some with wheel spacers? I know that's not exactly ideal... Thanks for the help guys!

think theres a few things to consider. first off im not an expert but these would be the things i would consider. 1. suspension: do you plan on hitting sides? plan on changing wheels or offset possibly in the future? can you afford the same width tire your setting up for if you dont have alot of room when done? id consider atleast a gap of 2" however that is mininum at best in my opnion simply cause of tires do expand a little when youve been driving for a while on them. especially cheaper brands that you dont hear of on a regular basis. due to cheaper materials. if at all possible id narrow the frame too. but it will totally come down to the truck, wheel offset and tire width