All Classified forums require a Site Supporter subscription. It is only $25 per year and you can buy and sell whatever you like on the forum. To become a Site Supporter, go to Your Profile and select "Paid Subscriptions."
have someone look at the linkage while you push the clutch like Bake74 said. it could be multiple issues or just one. how's the clustch pedal? does it wobble? how's the z-bar? is it loose? is the linkage adjusted correctly? also, does it go into gear with the truck off? on my 76 Blazer one of the shifter pins fell into the trans and locked it up in reverse. pull the shifter and found the pin jambed between gears.