Headers VS Manifolds
1. Depending on your build the difference between headers and manifolds can be small or very large.
On my build for example…… I lost 1.42 seconds and 8 mph in the 1/4 mile (this is mostly exhaust change related but other factors, Im sure played into this). My build is not typical….. The engine set up is high compression and high RPM, the worst scenario for switching back to manifolds.
2. I look at it this way…. You have not driven the car with drive train you have built so you won't notice the loss…… The first time you run it is, what it will be.
Again, my personal example…… My car was fun and fast with headers and it is still fun and fast with manifolds.
3. If you go manifolds, you should at least run the best flowing manifolds that will fit your application.
My advise…. Go with manifolds, get it on the road and enjoy. You can always put headers on later if you feel the need.