1.3 overall height difference is .65 larger radius. So roughly 5/8 of an inch. If the 235/60 has more space than this in any area, the 225/70 should be okay, but ride height can be a big factor. If its stock, probably no problem. If its turned down at all, it might rub.

Go browsing pictures of drag cars. 27.4 overall diameter with 6" tread isn't far off from a 27x4 front runner size.