I'm surprised he sold you boars when you specifically said you wanted to raise some for bacon. Boars from traditional breeds are normally not kept on beyond six months - by which time they have reached "pork weight". This is because of the risk of boar taint. Running them on to heavier weighs increases the risk, as they are maturing sexually.
Now this is a can of worms, because some people can detect boar taint, some can't. Also, it's less prevalent in some breeds than others, and can be affected by a whole host of things, including age, cleanliness of surroundings, environmental conditions, feed, etc. I've written a piece on this subject for the November issue of Country Smallholding magazine.
Personally, I wouldn't worry about it at this stage, but I would get those pigs away asap. You can make bacon and ham out of younger pigs - the only downside is that your rashers of bacon may be smaller because the "eye" of the meat in the loin is smaller.
Good luck and let us know how you get on. Email me if I can be of any help:
tudfultamworths@hotmail.com Liz