Here is a page with some info on installing an H1 into a catterham. which I know is a little different than what you're planning on building. None the less it's a 2.8l 400HP V8 based on the Hyabusa engine you're thinking about using. It only weighs about 200lbs. which is only about 50lbs. more than a regular Hyabusa engine and you get 2x the power and displacement. I was initially going to recommend you use the 4g63 for it's ability to reliably produce large amounts of power from a relatively small 2.0l displacement engine. Also the 4g63 can do this fairly inexpensively. a stock rebuilt 6bolt (refers to the # of bolts holding the flywheel to crankshaft) 4g63 can be purchased for just over $1200.00 which is capable of 350-400HP, And if you wanted to spend a little more, for around $3000.00 you could have a freshly rebuilt fully forged 6bolt 4g63 capably of reliably handling upwards of 600HP. However after reading a little more about your project, and more so your budget I found the H1 Hyabusa motor would probably better suit your needs. well I hope this is of some help/interest to you, and good luck with your project it sounds like it will be pretty sweet. Oh one last thing I didn't see a clear outline as far as your power goals for the car. Also you said you wanted it to be NA yet you want to possibly use E85. As far as I know you don't realize many of the benefits of E85 unless you're running forced induction, running very high compression pistons or extreme timing advancements because of it's high resistance to detonation. It has an anti-knock index rating of around 106-110 octane depending on where you live. I could be wrong on this, so please inform me if I'm mistaken. "Whether you think that you can, or you think that you can't. You are usually right." 'Henry Ford.