Jon, that's funny that you mentioned a 1936 Ford. When I was in high school I wanted to buy a 1936 Ford but my dad told me no. He said it has skinny tires and mechanical brakes. You'll kill yourself. Look for something newer.
So I found a 1942 Packard. My dad rolled his eyes and said,"when I said find something newer, I meant something like a 65 Mustang."
Well, Father knows best.
Ever since then I've owned nothing but antique cars and trucks. I'm used to driving them and unlike most people, I'm not used to driving modern vehicles. I am very well aware of all of my vehicles capabilities and limitations and I never drive them beyond what they were designed to do.
In fact, I have virtually no desire to "upgrade" or"improve" on the original design. I drive Old Roy on the freeway at 55 or 60 and never make any attempts to go any faster. I've made it up to the high 60s going downhill before..
If you can get your 1938 truck to drive comfortably between 50 and 60, that is all the faster that you would want to drive, anyway.