4mm vs 6mm back glass. What's best?

[Bennyt]

73-76 back glass is 6mm and 77-91 is 4mm. Any benefit to using the 73-76 glass on my '90 CC. Quieter, stronger? Both are the same price and appear to use the same seal.

 

[Turbo4whl]

Thinner glass was for weight saving. Square trucks were designed when fuel was $.30 a gallon. Then the first fuel shortage and price hikes. Lots of items changed in the square years. More plastic too.

 

[Bennyt]

Thinner glass was for weight saving. Square trucks were designed when fuel was $.30 a gallon. Then the first fuel shortage and price hikes. Lots of items changed in the square years. More plastic too.

...but is there any advantage? I'm adding 50 pounds of insulation to the interior so I doubt an extra pound or two of glass would kill my mpg

 

[SquareRoot]

All depends how you like em', thick and curvy or slim and hip. Potato.... potato

 

[Scott91370]

It may be slightly quieter with the 6mm. I'd go that route if available.

 

[SquareRoot]

Depends which engine you have. If it's the 305, stick with the thinner glass. Lol

 

[Bennyt]

Mild RV 454 w/ headers. But adding a small centrifugal blower for towing when I build a 502.

 

[TotalyHucked]

No noteworthy advantages or disadvantages, as stated above it's just because GM was trying to save every ounce they could in the '81-up trucks. They even use the same gasket.

 

[Bennyt]

I think I'm going to do the 6mm just because I can and it might be quieter.