Chain is about $90. aslong as it hasn't been jumping teeth the rest should be ok. It can be replaced without removing the case from the truck. Just the tail housing lower acess plate and would probably be a good time to replace that front output shaft seal. http://www.southerngear.com
should be able to provide the parts at a reasonable price.
Nice nick BTW [img]/wwwthreads_images/icons/cool.gif[/img]