[smbrouss70]

Mine had utility buckets, plus I am about 6' tall, so I did this...

Originally Posted by bamachem

This is the bolt pattern in the floor of my 72 K5 where the REAR feet of the driver seat mount. The holes on the left line up with the seat. The holes on the right were plugged with extra bolts. All holes appear to be factory, with captive nuts below. I plan to move the seat back to utilize the mounting holes on the right.



Here's the plate I used. 4" wide X 1/4" thick galvanized flat bar (carbon steel). I cut two 5" long sections.



First step is to unbolt the front feet of the seat and to just loosen the rear bolts - but do NOT remove them from the original holes. Slide the steel plate under the feet and line it up with the edges of the OEM seat frame and mark the holes. Mark the plates for both feet.



Drill the holes and mount the plates to the floor using the OEM bolts.



Now take the rear seat mounting bolts out of the original holes. Slide the seat back and then put the bolts in the rearmost set of holes. Now you can see that the front feet slide back and onto the plates you just mounted up front. Mark where the new mounting holes need to be, remove the plates, drill the holes. Go ahead and paint the plates at this point before you install them back in the truck. Paint all edges and holes well. Finally mount the plates with the OEM bolts on the floor hump again.

NOW USE HIGH-GRADE HARDWARE TO MOUNT THE SEATS TO THE PLATES - Grade 5 or Grade 8.

No need for welding anything as you can easily get to the bolt heads and the nuts. I would suggest using a split washer on each to make sure they don't loosen up with time/vibration.

Result? About 2" of additional leg room! It's almost too much leg room now.