the ole 67 is loud inside and im not smart enough to figure this out. floor, top, back of cab, and doors have the foil back insulation and new lmc door seals. also has carpet. I did the floor first and it helped but cant tell any difference when I put it in the doors and roof.
don't hear wind noise, but seems like its coming around the doors, but not sure. maybe just the way it is...….

 

Ive got a 67 too. Carpet, new firewall pad. Its a shortbed though so maybe the muffler is too much under the floorboards.
Maybe consider the placement of the muffler further back. A different muffler setup.
My 67 is loud too, I’ll be putting some sound deadener pads inside the doors

 

Sounds is a challenge. Products like dynamat work well but are expensive. You can also look at MLV (mass loaded vinyl). It might be easier to install over your current insulation.

I put dynamat like material (tar paper) on as much sheet metal as possible. I put it in the doors (back side of door skin) of my truck and they no long sound like a tin can when I shut them. The best way to stop sound is mass.

Good luck

 

The cab is a big drum. Any noise on any part of it causes a drum like reverberation to the other panels. My 71 is fairly quiet now, but it took some work...

1. Dynamat on metal surfaces that normally make an "active" noise. I don't know what else to call this. If you flick it with your finger and it makes a long sound then it needs something to "deaden" the noise to just a thump. I installed a dynamat competitive product from Metra that is 1/5 the price and works the same. Buy a roller to apply it correctly. Preferably in the summer. You DO NOT need full sheets or full coverage everywhere. Just enough to deaden the panel. I cut the pieces into squares and strips and just apply enough to get rid of the drum noise. Installed this in the door outers, door inners, floor, back of cab and cab corners, roof, and firewall. $100 and some time.
2. After the reverb noise is done, then you can work on the general road noise. This is just jute pad with aluminum foil backing (for heat). I bought Soffseal Summit has it with free shipping over $100. This goes under the carpet, and behind the headliner. Works awesome. Just use spray glue on the jute side.

3. Windows: You said you didn't have wind noise, but the window seals and door seals will help with road noise too. Replacing these are a full day project but it helps.

Hope that helps. I have not tried the firewall insulator yet, but may give it a shot. My 71 has a 390 with fuel injection that roars. However, we installed a Vintage air system that is no fun to remove and reinstall.

 

Recommend “Q-mat” sound deadening pads. Better price too.

 

thanks everyone. the window felt is new also. what about under the cab? I have even stuffed the cab corners full of towels and it doesn't seem to help. of course the drip rails catch wind also.
no firewall pad, but I put the foil back stuff up there best I could. I even taped up the passenger door where it meets the fender and cab still no change. I guess it is what it is....

 

Towels in the cab corners will encourage rust.

One thing to keep in mind is that newer cars are engineered to cause less turbulence around the windows, etc, so you might be suffering from unrealistic expectations. Vintage cars are just not as comfortable as newer cars and that's the plain truth.

Does your truck have 'West Coast' style towing mirrors? Those cause a lot of wind noise.

 

small mirrors. the towels were just temporary. these things are all steel too which is louder than plastic I assume.

 

What kind of tires do you have? My 69 that I just purchased has 31 inch knobbies and they make quite a racket at any thing over 35mph. i plan to put more conventional tires down the road.

 

Window seals were mentioned, but I'll add that specifically the rear window seal, but especially the window itself if you have a slider, can have a huge influence on getting rod of unwanted outside noise. At least on some trucks.
My '79 standard cab has only insulating pads and carpet (no stick-on stuff) and was somewhat decent. When I changed from the original slider to a brand new CRL slider I could tell the difference literally within the first 50' of driving! Yes, it was that obvious.
Surprised the heck out of me, as all I wanted was the outer ridge for attaching a boot between my cab and camper shell. Otherwise the old window worked just fine. Glad I changed it and the gasket, because the noise intrusion was surprisingly high from the back of the cab.

Otherwise most of my trucks will be getting Lizard Skin sound deadening spray throughout. Probably on the outside, but I haven't really gotten that far yet. The outside just means I don't have to gut the interior and that might be all the answer I need to decide to apply it to the outside.
It's a spray-on or roll-on product that comes in two flavors. Acoustic damping and thermal barrier coatings. Acoustic goes on first, and if desired to reduce heat, the thermal barrier coating goes on over that.
My Bronco is a reverberating torture chamber and heat magnet. So I'm doing both.

Good luck.

Paul

 

new slider from lmc and seal. I bought it right before they went up in price luckily. I have adjusted on the doors so much I may have screwed them up.
I like the spray on idea. probably going to do that under the cab. thanks....

 

1Ton
Have you used the lizard skin yet? Did It work well?

 

Hey Crewcab, thanks for checking in. Unfortunately no, I have not had the chance yet.
Glad I didn't buy it and let it sit on the shelf like so much else though, because most of my junk has been put on hold for awhile now. And even more so since mom got out of the hospital two weeks ago.

But I will add that several people I talk to regularly have used either one, or both of the Lizard Skin products and by all reports saw excellent results especially in the sound department. Lots of positive comments, so I'm still planning to use both.
In my case, I mentioned the Bronco, but I also plan to do the cab of my '79 over again, and apply both coatings to the inside and maybe even the outside of my factory camper shell. Over the exterior I'll be painting it too.
Reason I'm thinking of putting the heat barrier on the outside is that the fiberglass is deteriorating rapidly now from sun exposure and I need to fix and paint it anyway. If the Lizard Skin is a durable exterior coating (I have not checked into that yet) it might make a good first coat to stop the fiberglass from further damage.

If I didn't already, I'll mention that my '71 is much quieter than my '68. At first I thought it must be the carpet in the '71, but the more I think about it the more I suspect just the rubberized undercoating products I used on it's exterior underside may have had a lot to do with the lack of annoying resonances.
It's certainly not what anyone would call "quiet" by modern standards, but it's absolutely more quiet than the '68 with it's Raptor lined floor. The hard Raptor coating does not seem to reduce either heat OR noise. Both are unacceptable even to me.

Anyway, you only asked whether I'd done it yet and I gave you more blather. Basically though, I'm still a fan from all reports and plan to use it when I get another chance.

Paul