Does the starter turn if you connect jumper cables to the downstream side of the relay? If not, the relay isn't the problem. Most Hydramatic equipped engines have a starter with a solenoid bolted onto the top of the starter. Does your truck have one that's a completely separate unit?

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!