I am attempting to remove the intake from my 1977 280z.  There appears to be only 4 bolts that hold it in place, the service manual confirms this but I can't seem to get it to budge.  I did some searching and found a thread about a similar situation but it was a 1976.  They were saying there was two hidden bolts on the bottom.  I assume that was specific to the 1975-76?  Any input is appreaciated!  

 

 

The FSM doesn't really cover that very well.  Here's a better picture from a parts manual site.  There are clamps below that hold both manifolds at the same time.  You might get just the intake off alone, but most people remove both at the same time.  78 used studs and nuts with "yokes" that clamp the manifolds.  They look like thick curved washers.

http://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/manifold-egr/from-aug-76

I assume you've disconnected the AFM and linkage.

You can see the 4 on the top. The Intake is also connected on the bottom with the exhaust manifold by 4 heavy washers and nuts that overlap the exhaust and intake together.  If you remove the heat shield first you will see them and be able to access them better.  Be prepared, they are held on by studs that will probably be rusty and often snap off.  Maybe you will get lucky and be able to loosen the nuts enough to remove the intake without removing the exhaust.  Also, the intake and exhaust use the same gasket. You might have to replace it which means pulling the exhaust also.  A lot will depend whether or not any sealant was used on it before.

And you don't have to remove the heat sheild first. It just makes it easier to see the nuts if you do. You can feel them with your finger. 

Thanks guys, ok that makes more sense, I have another intake that I am installing and was puzzled as to why there were no bottom holes.  I am going to install a header so I am going to have to remove the exhaust manifold as well, but didn't even want to think about working on those rusty bolts until I had the intake and heat shield out of the way.  

Read over this if you have time. Great write up with plenty of pictures thanks to Blue/240260280

http://www.classiczcars.com/topic/39674-77-280z-head-removal-step-by-step-photos/

A mirror, long socket extensions, a wobbly socket attachment, and tape could all come in handy.  Working on them is an acquired technique and can be very frustrating in the beginning.  Make sure that all of your surfaces are clean and flat when you reassemble because the exhaust system is prone to leaking.  Even new headers sometimes need some minor surface work.  If you think that stud is about to break, stop and think hard before deciding to go ahead and snap it off.  Heat, and PB Blaster and tricks might be better used early than late.  The same problem is there with the thermostat housing bolts.  They like to break too.

23 minutes ago, siteunseen said:

Read over this if you have time. Great write up with plenty of pictures thanks to Blue/240260280

http://www.classiczcars.com/topic/39674-77-280z-head-removal-step-by-step-photos/

Oh man, this is perfect!  I have one bolt holding the heat shield on that is rounded off, all the rest are out.  Damn..

Vise-Grips worked good for me.  I didnt think about using a mirror until I rounded one off.

Good luck.

Cliff

38 minutes ago, siteunseen said:

Vise-Grips worked good for me.  I didnt think about using a mirror until I rounded one off.

Good luck.

Cliff

Yea, I thought I had it with the vise grips until I didn't.......

People sometimes have to grind them off.

I had to go get one of these. Of course, a socket wont fit for some of the heat shield bolts.

 

m.harborfreight.com/9-pc-38-in-drive-metric-bolt-extractor-socket-set-67894.html?utm_referrer=direct%2Fnot%20provided