I have a 91 305 that is fully stock and am looking to upgrade the exhaust system. Im ordering my magnaflow muffler soon.

Ive been told Dyno Don is the way to go. How much of a hp gain will I get with new headers? Is it worth the money?

Also do I need a new Y pipe or can I use the stock Y pipe.


Im not building a race car, just a nice DD that sounds good with a little extra power on a highschool budget.