I remember the straight axle front ends as replacements around 1961. Before then, early fords(32-48) had learned they could change the original front axle with a Model A axle to raise the front about 2". They also used spacers between the front spring and frame mount for even more raising the front end.

Why did everyone want to raise the front of a car? Back then many gassers used recap slicks. The recaps had hard rubber----we used to kid that they were hard enough to strike matches on. Even the first custom slicks (M&H) were very hard compared to today. So we raised the front end to gain forward bite. Raising the front end got to be carried to the extreme and some dangerous cars resulted. NHRA finally mandated the crank centerline could be no higher than 24". Even at "only" 24", there were some hairy rides in the altered and gas classes----especially with superchargers.

Many of the lower gas classes (heavier cars) never changed to straight front axles----just raised the front end as much as possible using longer springs. Some raised only the engine leaving the front end alone.

That was the neat thing about the early days, everyone had a free hand to do what they wanted(within reason) to get their car quicker. Their were very few guidelines in the NHRA rulebook. I don't remember roll bar specs until about 1961----and then it was only tube diameter/thickness and clearance above the driver's helment.

This lack of rules also led to very long times in the tech inspection line especially at Detroit and early Indy events.

Ah, for the good old days---especially since I was much younger!