You can buy and original style that can stand the pressure but it'll cost a lot more than the aluminum one. Luckily I bought my aftermarket original (with automatic tranny cooler) back when I could buy it for $245 which was quite a while back.
Today, or a year ago, I bought a Walker aluminum delivered to my front door for exactly $200 and it came with a nice high pressure radiator cap and automatic cooler in the bottom. Fit quite well.


1937 Chevy Pickup
In the Gallery
1952 Chevy Panel
In the Gallery
More photos
1950 Chevy Coupe
Pictures!

I'd rather walk and carry a Chevy hub cap than ride in a Ferd.
I can explain it to you, but I can't understand it for you smile