Over bore pistons

198 rod is 7.005, while a 225 rod is 6.7 so there is mucho difference. 2.2 has a deck height of 1.610, along with a 7.005 rod will give you 0 deck height (+-.01) so a 2.2 on a 225 6.7 rod will give you -.030 in the hole at least. Check here: http://www.slantsix.org/articles/stroking/stroking.htm