Then power steering is added, then later it is realized, the 18" original steering wheel is now too big.
There are 15" steering wheels that will fit but they don't look like a 49-53 truck wheel.
Reducing the size of a stock wheel is possible but it requires a fair amount of manual work so only a few go this route.
There is one company that reduces and recasts to a result that looks brand new. Labor costs are high.

https://www.motortrend.com/how-to/1208cct-reclaiming-stock-steering-wheel
http://67-72chevytrucks.com/vboard/showthread.php?t=457422
https://qualityrestorations.com/chevyreduced-diameter/

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."