dynamat/insulation question

I usually build 40's 50's customs, don't do many older cars. But I've got a 34 Terraplane in the shop I'm "street rodding" for a guy. It has a remove-able trans cover on the floor.
My question is: should I bolt down the cover, then Dynamat over it, as if it was a solid floor? Or should I insulate the floor pan, carefully leaving the trans cover separate, and insulate that independantly? Will leaving small gaps make any difference in the insulation value? I know that screwing the over down might be a pain, as the screws will compress the insulation, and make dents in it, or else stick up too high.
Is it really that important to be able to remove the cover at some time in the future?????
Thanks!
(Yeah, I know it ain't trad, but we have a lot of rod builders here, and I don't frequent any other forums!)

 

small gaps are fine, I would do the floor, and the removable panel separate for removal. I have done this in the past with no problems.

the only thing dynamat does is ad m*** to the sheet metal part to reduce vibration, and heat, so it does not have to be perfect... or even close to perfect

 

I've never installed it, but I've seen custom "kits" that only put the dynamat in certain places to cut down on vibration. usually evenly spaced out on large flat areas-the ones that kind of ring when you tap on them.

 

Agreed. And you are correct, sir.

BTW there are two Dynamats. One is plain black and the other has an aluminum skin on the non-adhesive side. The aluminum one is more expensive but might be better on the floor pan and firewall. The plain black is fine for the doors and sides of the cabin.

 

Forgot to mention. There is also a spray-on Dynamat for nooks and crannies. It is extremely expensive and as an alternative you can use a good undercoating spray and achieve the same result for a lot less money.

 

Use the foil backed as it does not lose adhesion via heat like the black ****.
The spray on sound deadener retains water and is junk (last I knew 6 or so years ago)
undercoat spray would be alot better alternative 1/2 the cost, and does not retain moisture

 

OPTION 3

put the dynamat on the bottom of the trans cover to the trans side of the access panel/

 

I took option 3 on mine has worked out great.