I'm not familiar with the dash in your truck, so take this one with a grain of salt... This is a dash mod I did for a Studebaker truck, removable dash panel and gauge pods made for a curved panel... Starts on post 68 and I believe goes through to post 98 for the conclusion... May work for what you're doing..

http://www.garagejournal.com/forum/showthread.php?t=182565&page=4