That is probably your best bet as once that original foam is dried out, it is all dried out and will continue to crack.
I now wish that I had stripped my entire foam off prior to covering it with leather which took quite some time.
The brown one that I did awhile back sat in my front yard without a windshield screen protector (cardboard) and it did mess up around where I had redone the factory speaker holes. I am almost redone with that repair. I did two different dashes, the brown one and another red one that I covered...
First thing that you need to do is figure out what smog laws you are under as different counties in CA have different rules. If you are subject to biannual inspections, don't even think about an LS/LT swap. Huge PITA in CA. My local ref told me that yes an LS/LT would run cleaner, better blah...
A little update, I am slow, but at least it is going the correct direction.
A little before and after, along with a what will be replaced and with what (a lot of "W"s there).
You can redo your stock dash to come out looking very nice with a little effort. There is a thread in the interior section on how to do it.
I am getting ready to do my second dash and I will be installing tweeters under the dash with custom speaker grills. Still debating whether or not to...
Stole the interior trim pieces that I could from the donor Suburban and purchased a couple of aftermarket parts online.
But they were all the wrong color, not anymore.
The truck didn't have a headliner and was missing a bunch of interior trim.
After screwing around trying to make a donor Suburban headliner board work, I gave up and stole the board out of an 83 CC that I have.(will be for sale soon!)
That is real 100% 16oz Scottish Wool.
I even have some...
...then coated and textured the panels.
I will wait about a week and hit them with some Dark Carmine that I got from USA1 - turns out it is a perfect match.
I liked the color so much that I had some Base Coat Urethane and Gloss Solid Body Urethane paint mixed up to match for...well, not sure...