i have an 82 chevy k20 with dana 44 axle, i try to engage four wheel drive and for some reason the front tires wont pull, the front drive shaft spins and they are manual locking hubs and i have those both locked in, im not sure if the truck has a dash light for the four wheel drive but there is no light on, any suggestions on where i should start?

 

yp try your hubs they may be shot
also try going from drive to reverse i had a truck like that and i just had to rock it a little bit for it to catch
also it could be your differential isnt engageing thats my first thing i woul check
jack the truck up put it on jack stands and lock the hubs then try and spin the tires if they are not spinning freely they arent engaging like they should
make sure your trucks in neutral as the transfercase will stop the trucks tires spining easily
meaning the bearings are bad or that the splines on the axle shafts have been worn out to the poin of needing replaced
also they axle shafts may have slide out of the teeth inside of the diff that will cause it too