I have a 1978 280z that I'm slowly putting back together. After I install the heat and sound prooofing I'm going to need the firewall insulation. Will the pieces that MSA, Black Dragon sell for the 240z work in the 280Z???

They should, with minor differences.

Make your own. It is easy.

The black rubbery material is ~ $11 at pep boys. It is an oil absorbing sheet

The thick insulating backing is floor matting from Walmart or Pepboys $20

A Can of spray adhesive ~$10

Two sheets of poster board from walmart or a craft store will make a nice template. ~$13

Details here: http://www.classiczcars.com/forums/showthread.php?43137-Modern-material-for-making-new-interior-firewall-insulator&highlight=firewall+insulation

I went the same route as Blue, using his tips and steps in the linked post. Mine is a for an early 260 that has a 3 piece pad. I ended up making it into two pieces for ease of making and installing. I used the same oil absorbing sheet and found it at O'Reillys, backed it with high density foam in the form of a camping sleep pad found at Wal-Mart. I will say that the oil pad is some tough stuff, it does not cut as easy as you would think.

I am almost ready to install it, but I am missing one of the snaps for holding the carpet. Blue, where did you find your snaps, and did you attach them only to the pad you made, or screw them direct to the firewall? My originals are only attached to the pad with screws from the front and a small piece of fiber board on the back side.

I did blue's suggestion and it came out ok. Then again I'm not making a show car.

Aluminized bubble wrap, on the ENGINE side, is what will really keep heat out of the cockpit. That and sealing all the holes, replacing grommets, etc. The rest is just soundproofing.

I just dropped off my early 260 firewall insulator at a place called quiet ride solutions in stockton CA, they said they supply LMC which is the parent company of black dragon. They took a detailed CAD outline of my firewall and made a template that fit my car exactly. They definitely have a 280z firewall insulator and as of today they have a 260 as well. http://www.quietride.com/ i have no ties to the company, just awesome service