Hi MicTheGreaseMo,
Thank you for your enquiry.
"can i go down 2 a 74mm pulley with a stage 3 cam kit, ported blower heads & elbow without a a2a or w2a set up?"
The 74mm is 2.9 inches 15PSI pulley, a physically smaller pulley can only be used when the motor is intercooled, cammed and dyno tuned or has a combination of all 3.98 Octane fuel must be used when installing an aftermarket supercharger pulley.
Without caming, you can go up to 20PSI (56.8mm) pulley with the Air to Air Intercooler kit. We also offer an INTERMEDIATE INTERCOOLER PERFORMANCE KIT allows you to drop from a 3.4 to either a 2.8inchs 16PSI or 2.7 inch 17PSI pulley, on a virtually stock car and all without the need of an expensive tune**. In addition, car idle and drivability remain unchanged even with the factory tune!
https://www.maceengineering.com.au/epages/shop.sf/sec8fe1347d35/?ObjectID=1469589
In your case, you have ported blower heads & elbow so a tune would be required.
If you have any other questions, please do not hesitate to ask.
Kind regards,
Michael
