That crossover is available aftermarket for abôut $100. It flows much better than the factory piece, too. The factory pipes were double walled and renowned for collapsing internally. You do the golfball test: if a golfball dropped in one end doesn't freely roll out the other side, it is collapsed.
I replaced the crossover in my 95 K2500 Suburban when we did the head gaskets last year. You might want to replace the turbo down pipe and the exhaust as well while you are under there. It really improves the power.
http://www.ebay.com/itm/Diamond-Eye-Cros...f6a&vxp=mtr
The whole exhaust adds about 20 horsepower and a ton of torque. Really noticeable improvement.
I got the Diamond Eye system off of ebay, directly from Diamond Eye. Gives you a couple more mpgs, too.
http://www.ebay.com/itm/4-Turbo-Back-Exh...010&vxp=mtr
They offer free shippng which is a big deal on a box this big and heavy.