1st gen bed differences

can anyone explain the difference between 72-89 8 foot bed and a 93 8 foot bed. When I look up tri fold covers they say there is a difference. Birdtracker

same basic bed, but in '81 body lines and tail lights changed. also some mounts are in different spots.
'72-'80
'81-'93

so this website says their tri fold only fits 75-89.
https://www.amazon.com/Tonno-Pro-42-208-TRI-FOLD-1975-1993/dp/B00M4917KW

of course they are out of 93 ones. Birdtracker

other websites say 81-93 will interchange so I am going to order one Monday and take a chance. Birdtracker

The 81-mid 89 beds (we think) had brackets welded to the crossmembers for the bed floor that contacted the frame for support. The 1990-ish-1993 beds did not have the brackets, they were built into the frame when it was bent. Those are the only differences 81-93. They should not apply in your case. There was a older moparts thread titled 81-93 bed differences about this from 2010 or so but it seems to be lost

you never said if you got this or not. remember, it is amazon, so if it doesn't fit, just return it.