which heads lq4
TECH Senior Member
Joined: Jun 2016
Posts: 22,290
Likes: 3,615
From: Central Cal.
Yeah, just specify iron guides instead of bronze. You need roller rockers with bronze as they can't handle the side loads stock rockers put on valves. Iron guides handle that with ease.
Manganese bronze guides do a better job of dissipating heat and lubricating but because it's a softer metal it can also wear before the valve does. Race engines aren't built to go 100,000 miles and it's for these reasons alone why bronze guides are preferred over iron guides.
