[SilverMiner]

eighteenninetytwo -

To answer your Q1, that is what I have done in my 1980 Suburban. I don't have a build thread to show you full of useful photos, unfortunately. Also, I have not completed the process throughout the entire rig, so my results are still preliminary.

What I did was lay down FatMat over nearly the entire floorpan, then cover everything with closed cell foam from Lowes or Home Depot, and then instead of purchasing relatively expensive mass loaded vinyl with it's expensive shipping I instead put down one of the heavy vinyl floor mats from LMC and put new carpet over top of that. One problem I do see coming up is correctly reinstalling the sill plates with all that thickness. Probably will have to trim the foam and LMC vinyl back.

I have not completed the rear cargo area or the headliner upgrade yet - waiting for warmer weather. Despite not being done, the difference is remarkable and noticeable even to people who rarely ride in my old beast. I can already tell that by reducing road and engine noise I will have comparatively amplified the wind noise, so I am resigned to the fact that I'll never achieve Cadillac levels of quiet. So far the improvement has been more than worthwhile, and I look forward this spring to finishing the headliner and cargo compartment and seeing just how far I can go. Using an un-calibrated free decibel meter app on my phone I've already reduced overall noise levels from ~81db down to ~69db, completely un-scientific but nothing to sneeze at.