I am posting on this topic for the benefit of others who may want the faster spooling 16 cm2 turbine housing for their First Generation Turbo Diesels, or for the better airflow and lower maximum egt's on their Second Generation trucks. The 16 is the smallest housing for a First Generation that is a direct fit. The smaller housings are 1. 25” longer on the outlet end because most of them have wastegates. Therefore, the downpipe will be too close to the heater box on most First Generation trucks with the 12 or 14 cm2 housings. On the other hand, using the shorter 16 cm2 housing on a Second Generation Turbo Diesel involves moving the entire exhaust system forward that 1. 25” by bending the hangers, and revising the stabilizer rod going from the exhaust to the transmission mount bracket.
With heat warping the entrance of the turbine housing, and an accumulation of rust, the turbo seems quite “stuck” on most older Turbo Diesels. I have found the most successful way to separate them to be this: soak the mating area with rust penetrant; tap on the compressor housing with a hammer near the outside diameter, going across for sequential taps, while spinning the compressor wheel manually to be sure the exhaust wheel is not binding on the exhaust housing. If it starts to scrape, tap the parts back together slightly where you last hit the compressor radially. Then, continue tapping to separate them, keeping the turbo center section and the exhaust housing aligned as well as you can, as determined by lack of scraping on spinning the wheel.