So.. time to figure out what head for my 67 440HP. Basically stock rebuild and the car is going to be a driver not a track car. 480ish cam, 2355 pistons, holley SD intake, HP manifolds. I would like the stock straight spark plug configuration which makes me lean toward stealth heads but I have heard you should take your new stealth heads to a machine shop and have them go over everything. So basically your $1000 plus shipping stealth heads probably will cost you $1500 when you are done, yes? So would rebuilding my 1.74 valve 915HP heads with exhaust seats be cheaper and give the same performance? What would you do? Thanks.
I bought a set of Stealths to improve the flow and avoid replacing the seats, springs and valve guides on a set of 1965 615 heads. The intake seat on the Stealth heads is small and it will require a valve job to it up and get close to the advertised 290 CFM flow out of the box. The valve guides and springs worked with my application but the spring seats were "too thick" for the spring compressed height with a fairly mild cam.
I ended up paying for the valve job and different spring seats, so yes, you can expect to spend around $1500 to have a set of decent flowing heads for your application. I figured that a valve job, seats, bronze guides and certainly springs would have run about $850. With my cam I flow around 270 CFM vs 210 CFM with the 516s.
My 383 (390, .040 over) made 480hp/460tq with an Eddy 1407 carb, Performer 383 intake and 2" dyno headers with around 10:1 compression. It could have been richened up some and would probably have made a little more. Certainly more with a better carb and intake. Cam is a custom Bullet .485/.490, .227/.234 at .050. Those heads make a difference and yes I would do it again.
Here's a link to the flow sheet.
440 Source flow after a valve job
