PLEASE HELP with rim problem!!!!!

i know i posted this before but now its time to actually buy my rims and i need to know if 20x10's are to wide to put on my 85 blazer thats bagged. can someone please tell me a simple yes or no and not a maybe answer. i got 20x9's now, is it going to make that big of a difference. i need an answer quick so any info would be apperciated, thanks. Jason