At 19psi you would make 330rwkw tops, that would be pushing it too.
Take it to the track and post your MPH. That will give a clearer idea, rather than having to decipher a weird dyno result.
Or put it on a Mainline.
Budget $1000-$1500 for flights
$1500-$2500 for accommodation.
Spending money is up to you. There are alot of threads already on where to go and what to see, have a look.
The RB25 (non NEO) head is very understated. Bigger ports than a 26, has VCT. The only thing that lets it down would be the hydraulic lifters if you are planning on revving it past 8500rpm.
IMO we need more events similar to this. Its getting harder and harder everyday for guys out there who have hypo street cars to get out there and enjoy them.
If only the was an event like Powercruise/GTR Challenge every month