I've been out of the game.New heads for 408
Oct 21, 2017 | 07:00 PM
#11
Staging Lane
Joined: Oct 2017
Posts: 88
Likes: 6
317 were cheap and aftermarket heads were expensive in comparison. However most 408's never performed that well on the top end cause they couldn't breath.
With a 408 you need to feed that beast. I would step up to an aftermarket head. They will flow more than any ported set of factory castings.
A good exhaust system will help too.
To Quote the late John lingenfelter
"The worlds's best cam combined with a poor set of heads will produce an engine that's a dog. But bolt on a set of great heads even with a poor cam and that engine will still make great power."
With a 408 you need to feed that beast. I would step up to an aftermarket head. They will flow more than any ported set of factory castings.
A good exhaust system will help too.
To Quote the late John lingenfelter
"The worlds's best cam combined with a poor set of heads will produce an engine that's a dog. But bolt on a set of great heads even with a poor cam and that engine will still make great power."
You think aftermarket over some stock 823/821 heads, I’m talking money wise compared to gains? Don’t the stock “Ls3” heads flow pretty damn well, especially for a 408? I could understand stepping up to aftermarket in the 418ci+ motor range, but for the 408 do you think it’s worth it?
Oct 22, 2017 | 12:25 AM
#12
You think aftermarket over some stock 823/821 heads, I’m talking money wise compared to gains? Don’t the stock “Ls3” heads flow pretty damn well, especially for a 408? I could understand stepping up to aftermarket in the 418ci+ motor range, but for the 408 do you think it’s worth it?
Testing LS Cathedral-Port Vs. Square-Port Heads - Hot Rod Network
Oct 23, 2017 | 04:57 PM
#13
Teching In
Joined: Jan 2012
Posts: 49
Likes: 0
1fastbrick - "in regards to that quote" on smaller motors like 5.3L I was always told big cathedral port highflow heads will lose some lowend compared to stock 243s for example. Same for big port intake manifolds and throttle bodies. Is that true for LS motors or kind of a old school idea for SBC?
Oct 27, 2017 | 12:22 AM
#15
Staging Lane
Joined: Oct 2017
Posts: 88
Likes: 6