Pistons and conrods. $10K is not a lot of money in the engine game, it will disappear very quickly. A larger capacity baffled sump would be beneficial as well.
How do you plan on making the extra power? You will not get that out of a tune only.
As you can see below, the difference in the flow path.
The photo is for comparison as it is for a later model, so yours will probably be a bit different. I couldn't find a direct comparison for the 3VZ.