12 Second N/A Slant 6?

I like what I am reading here now and seeing now that you're spending way more money than I once thought ( I was in the $2K budget range when you said not much money) I can now take this build seriously.

So we're looking at 198 Rods and 2.2L pistons: Awesome!
Aussie Speed Bolt ons: Also Awesome.

Since you are shooting for a street car and nitrous I know you are wanting to keep compression down but here is food for thought.

Ever heard of water methanol injection? Basically inject water and mehtyl alchohol into the combustion chamber to slow combustion. With water meth injection you can basically turn 93 octane fuel into 106-110 octane. I don't know how this will react with Nitrous but food for thought?