WEll, here is my recipe. 67 Slant six, running stock, mega miles but runs good. 100 bucks. 50 buck Holley 350 CFM 2bbl. another 50 got me a 2bbl intake and an adapter. Scored a CT26 Supra turbo for $60 off craigs. Carb hat is an old GMC Diesel piece, $12 at pick-a-part as an air cleaner. Blow off valve was 35, turbo plumbing and no frills exhaust was about 100 including the mandrel 2.5 U bend and the silicon adapters/clamps and 3" turbo ducting. All crappy welds were done by myself. Look terrible but they dont leak. All this going through a 2.76 or a 2.93 rear gear. Have not run this yet, but I predict a 9 psi boost, and every 15 reportedly doubles your HP so maybe 230 HP. Mileage should be decent, but torque will be huge and that gets you moving. 200-250 in a teen is way possible, but your mileage (cruising) and torque (under boost)will not be more than mine. Whatever works for you, how about a 2.2/2.5 turbo with a 5 speed out of a light truck? Mileage and up to 275 HP.