Quote: Maybe it's just me,but I don't think you will see much of a gain until you put the bigger camshaft in it. On the header subject,1 3/4" headers seem to be the ticket with mine. I ran 1 7/8" before thinking they were necessary. My dyno testing lately shows a hole in the torque curve that just does not get made up for up top with the bigger headers. In anything that launches at or below about 4500 rpm anyway,I am learning to like 1 3/4" headers more and more. Keith
No offense but I disagree that it won't be much gain. I had a 408 that was almost identical to this build, same cam. Went from mild eddies to indybrocks, and gained 4 mph in the 1/4. So I am going to guess 560-570 horsepower.
No offense taken! We all have different ideas on what works and why. I just don't think the best exhaust port in the world can move enough air with that cam/header combination. I believe it will need different valve events to make much of a difference. If he steps up the header size before the cam swap,you will most likely see more. Besides,he is running stockish versus "ported" heads,not Indybrock's with a relocated pushrod pinch. Even if the flow numbers were similar,port volume and air speed isn't I would think it will move the peaks up the rpm range a few hundred rpm,maybe lose a little torque down low and gain a little horsepower. I don't usually guess numbers on these posts as I'm sure his dyno is slightly different from mine,but I would venture to say a 20 lbs-ft loss down low for 20 hp up top.
