Help me spend +500 bucks

Thirst for more torque/speed; I know who doesn’t;
What’s the next step guys; what would you spend your next USD$500 in *(I know low budget)
This is what I have so far:
• Raptor100
• Brand new stock VP44
• 100+hp Injectors
• BHAF air filter
• ADJUSTABLE BOOST ELBOW
I want to bank the most possible HP with my next purchase (have stock turbo) and programmers added
(I kinda know the answer but want some input)

Banks High Ram intake manifold, helps improve the air-flow from the intercooler, lower egt's, and more boost with less back-pressure. Turbo-back exhaust if you don't have one already? A little bit past the 500.00 budget.

Would also be a good idea later on to invest in a good set of head studs, such as the ARP custom aged 625 kit. A little bit more in price, but a good idea if you decide later on to add some serious ponies under the hood.

I say head studs or save up a little more and get a larger turbo.

I agree with the studs and a bigger turbo. The ARP custom aged 625's are around 1,100.00, but well worh the money if later on some serious horsepower is needed, taken care of once instead of having to go back and reinstalling them again. The stock turbo is pretty much at it's limits with 100HP injectors and the tuner. For any more added horsepower, will need a 64mm to a 66mm turbo. The 64 is good for mainly a daily driver, while the 66 is good for the weekend drag-strip. Both the turbos are good for well over 500 plus horsepower. With the stock turbo, 100'HP injectors and the tuner, high egt's will occur, that's why I mentioned the Banks High Ram intake manifold will help with the egt's,back-pressure, and pair's up nicely with the Banks billet intake heater delete. A transmission upgrade is also recommended, input billet shaft,and upgraded set of clutches will help hold the power to the ground. The VP44 pump can handle the extra amont of fuel when needed, for serious horsepower a 12 valve p-pump conversion will be needed.