you can easily get into b16 territory with a 1mm overbore, some headwork, pistons and a cam - plus, you'll have a bit more torque then a regular b16. I've argued about this many times before, but I know a nicely built and modded D16Z6 will walk any stock b16a - and why? because the D16Z6 has a much wider torque band starting way down low - the b16 just starts to kick in at around 4000 or so. We got about 142 whp and 135 ft/p torque out of a D16Z6 built out of the above recipe - no more, no less. Yeah, if you want to go all out and spend the money, go with a b18c for NA but if you want the best bang for your buck, build the D16Z6 - and yes, the stock rods will hold up ok for your application - you can always have a set of ls rods sized to fit your engine for about $200, but then you will have to rebalance everything. I have stock rods in mine and rev it up to 8000 without worry.