The best bang for the buck would be swapping over a set of gt40 heads and intake. If you scour around the web, there are also quite a few used aftermarket heads like TF and AFR that can be had for a reasonable price. With the gt40 setup, you should install different valve springs. As for the intake, i wouldnt mess with just it by itself. No point in having an intake that will outflow your heads. As for intakes, you can also find alot of them for sale used also. When the guys sell of their smaller TF and AFR heads, they usually upgrade the intake as well. You can usually save around 250 dollars by buying the aftermarket intakes used.