Whats a realistic horespower gain for my Duster if I switched to headers? here are my specs.
74 Duster with matching 318 and 904. Both been rebuilt.
318 is 9:1 with a 340 cam and valve springs.
edelbrock performer intake and 600cfm carb.
Heads are basically stock except for a valve job.
But worst of all - stock 318 manifolds exiting into duel exhaust.
Based on what I have read the small block LA engines really benefit from headers. I was thinking about Dougs since they have really good fit minus the tti's price tag. This is just a street car. I would say once a year I take it to test in tune. With the above specs I can only manage low 16's. The car just dosdn't seem to have the power for a good launch but once moving seems to pull good. And I have a 3.21 gear with sure-grip. I would love to dip into the 14's but I would need more than headers to accompolish that. So how bad are the manifolds killing me in power?
Thanks for any input.