Is it a 3600 cab on a 3600 frame? The only reason I ask is my in a million pieces project I had a 3100 frame with a 6400 cab and shackles. I researched all over to resolve it. Finally loosely put the front end, running boards and bed on to see where the holes needed to be on the frame. In your case you would benefit with at least one stock to duplicate a pair of rigid mounts like others have done. Maybe someone that has done that can chime in with measurements.


Chip

'Rusto-Mod'
'51 Chevy 3600 5 window | C4 Corvette front/rear suspension & drivetrain | everything else looks old and stock
'92 GMC Sonoma GT #15 of 806
'91 GMC Sonoma GT Extended cab 1 of 1
Trucks, Trucks.....and more Trucks