I have a 54 Buick two door ahrd top that I decided to put a Camaro subframe under the front. Lots of people on the board said NO and that the original front end functions well. That may be true but it sure is not cheap to rebuild and add modern brakes. I have always liked my cars to ride right and handle tight. After compairing prices of building the orginal front end it just didnt make sence. I sell auto parts for a living and working through all my suppliers that I have collected over the last 20 years the money just didnt add up. I purchased a camaro subframe for $100 and added all new ball joints/ bushings/ brakes and bearings to it for less than $250. The gear box is in good shape but to reseal it is about $17. In comparison rebuilding the factory 54 powersteering box was an estimated $500 alone, and you have to pull the body to get it off. SO... our car club the Ratty *******s when to town cutting out the front end and adding the new one. After all the measurements were done mulitple times. We cut the frame just infront of the forward x at the firewall. Next we split the frame open and peeled it back towards the inside. The subframe went right inside and the we pulled the inner x back to it to give it more strength and welded around the seams. Plated the top/ bottom/ inside with over lapping plates and weled them in. Its strong as hell. The ride height is about 1 inch higher than the car was before with the engine in it and spacers on the control arms. I can now make the front end set where I want with readily available parts to drop it more. I added a few photos so you can see. We did all of the front end in one day, 4 great guys, some great fun and a wonderful project. We also installed a truck arm suspension to the rear the following two days, I will post that later. But years of building this car in my head and doing research paid off well. Notice how the frames are the same width and how well the lines matched on the outside. Hard to tell its not factory
I agree with your line of thinking. Better suspension design, better brakes, parts availability, cheaper overall, and a bolt-in GM issue sway bar can be installed.