The cheapest mod for you to do would be to get an H22a Engine swap... you can find a use COMPLETE SWAP (Everything needed) for $2000-$2400. If you get the JDM Motor, thats an instant 65 Horsepower Jump which would cost you probably $3000ish if you were to get a Turbo for the F-Series with the same results. I suggest going with the H22a1 (OBD I), for the best bang/buck ratio.

~Peace