Pretty sure it's just the cheapest crap fasteners they could find. Been working with alloy heads and iron manifolds for close to 40 years now and most of the Honda and Toyota cars don't do it
Gus
I don't recall the Neon's 2.0 or the K car 2.2 busting off studs, iron manifold, alloy heads
i was just thinking about the K car exhaust that had a spring between the manifold pipe flange and the retaining washer and nut.
i wonder if this would be anything to contemplate...........
a longer bolt of better material, a spring close to the shoulder length of the bolt [longer or shorter length of the spring, i can't say] then the cone washer [?] and nut.
just a musing thought rolling around in my noggin.
