My Gen1 SWB has bolt holes in the crossmember that the T-bars bolt to, and I've seen diagrams where there was a plate that ran from there to the front crossmember. Not sure if it was stock, some seem to have them and some don't. It looks like a pretty similar setup to what you guys have. I would like to get a plate fabbed up for that space! The photos I've seen of Kary's rig show pretty much full underbody plates, and he doesn't have overheating problems....someday for me too!

85 Pickup, Desert tan spray job, 3" Rough Country lift, Marlin shackles+bumper, Chebby igniter, 33x10.5" BFG's