I fabricate stuff like this too but I'm just an ol' farm boy with no access to or ability with CAD so I just pull it out of my rear. My last project was a 4-link in my brothers '70 Roadrunner. Came out purdy good.
Your 1940 Plymouth pickup sounds crazy impressive and I think I speak for most here that we need pictures. Maybe it even needs it's own thread.
https://www.dropbox.com/sc/eabkrvfpbyyzguj/AABZR4mVgNRNRMgbiBbDTdRha
Hello BikerTrash,
I wasn’t able to post the pics,
but see if the link works for you.
Thanks!