I'm beginning to run out of bolt ons for my '90 5.0. Currently I have a Cobra intake, GT40P heads, FRPP shorty headers, K&N drop-in panel filter with air silencer removed, March Pulleys (power and amp series), AC/Smog delete, full exhaust and 3.55s in the rear. Out of the following which is the most bang for the buck? : 65mm TB, FRPP roller rockers, electric fan or cold air/conical air intake? I want to spend my money wisely and avoid any advertisment hype. Thanks.