Here is a new product out for the 1973-86 bucket seats to be mounted in a regular cab truck. I have not purchased/tested these and I have no affiliation with the company, but the price is reasonable.
www.walterseandp.com
Bucket Seat Brackets 73-87C/K10 | Walters Engineering
Direct fit, bolt in, bucket seat bracket for your 73-87 C/K series truck. Recreate the rare factory option in your classic Squarebody with our 100% bolt in seat brackets. These do not require the inboard perches (see picture) that are commonly adapted from Suburban floor pans Seat brackets are...
