To get some more performance from your engine,headers would free up some HP for sure.You have many to choose from if you checkout Summit Racings site(you can also use a 15% discount code running now)Where abouts are you located in Ontario?I have a 73 318 engine that was a runner when pulled if interested for $100.It would be a great candidit for a rebuild,while you can still drive your car.PM if any interest.