I wrestled with this decision myself with my wife's '57 Chevy truck and decided to keep the solid front axle. I am very happy I did. The truck rides way better than I thought it would. It is a little hard when there's no load but I've got the cab very tight and with no rattles so it seems just fine. Carrying a load softens it out a bunch.
In fact, I just took this truck for it's first trip last week. A short trip to Austin to pick up a washing machine and a bunch of other stuff my son couldn't keep because he's moving from Austin to Colorado.
I was pleasantly surprised how it handled on the highway. I kind of figured that I would keep it at 65 mph but it goes so straight and feels so good that I went 70 to 75 the whole way. It even crept up to 80 a couple of times but I brought it back down to 75 because that's what the speed limit was. (I didn't put a cruise control on it but may at some point.)
The stock suspension was very impressive over the bumps with the load. The roads around Austin are kind of rough with dips and so forth and my Brother who was with me was very impressed with the way the truck rode with that load in the back.
On the front of my truck, I went with new stock replacement springs, an upgraded CPP tie rod, new king pins, shackles and pins. I also used the CPP 400 power steering box that mounts in the stock location. I used the 6-lug CPP disk brake kit as well. I just used new stock replacement shocks and they seem fine. I did find a great place to get the front aligned and the guy knew these old trucks well. He took the time to put the correct shims under the leaf spring pads to get the caster where he wanted it.
It is a truck after all and I wanted to keep it all truck instead of putting a car suspension on it. I also wanted to keep it stock height. It's just part of the nostalgia for me. Of course I did this truck for my wife but she wanted a truck too.
I'm not trying to sway you. Not at all. There are good reasons for upgrading these trucks to the other options mentioned here because it all depends on what YOU want. I just wanted to point out that keeping the straight axle can be a great option. Sure fit what my wife and I wanted just fine.
The drive train is a 305 TPI and 700R4 out of a '91 Z28 Camaro. The rear axle is a Dana 44 out of a '65 GMC pickup. It has 3.54 gears and a Trac Loc (posi). Wheels are 6-hole 16"X7" Wheel Vintiques Smoothies.
