1977 280z that I'm working on. P79 head and MSA header.  Did a lot of searching and can't find a definitive answer. My question is should I use all studs or studs and bolts

on the intake and exhaust manifolds. I did email Pallnet with the same question and his response was " I've always replaced the exhaust hardware with all studs", nothing about

the intake. Would appreciate your input. Thanks

I bought a ZX motor that had bolts on all of the manifold holes.  No studs.  I think that it's personal preference.  It's much easier to get a nut on the stud from underneath the intake manifold than trying to insert a bolt in to a hole.  One argument for studs is that when you put the final torque to it you're spinning steel threads on steel threads.  With a bolt it's steel on aluminum.  The same when you're removing them.  Studs probably help avoid damaged threads.

The four big bolts for the intake would probably make life difficult if you replaced them with studs.  Never seen big studs used there.

I like having studs for the exhaust for all the reasons ZH mentioned, but also when you are mounting the manifold or header you can let the studs take the weight.

So I should just order studs for exhaust and bolts for the intake.

Here's a whole thread on the subject.

 

The issue is the FSM says all studs, but on the actual cars that people have bolts were used on the top 6 holes rather than studs..