The turbo housing is .82 ar. I think it's to small. But I did install a big 10 blade turbine with 64 mm exducer. Yea I'm not real impressed with the stock bellows either. They are so thin ! I have run big and small precups ,and for me, smoke the same.
As far as the pump,the .290 should be fine. It usually takes me a couple tries on on each pump I build. Plunger size is not near as important as all the other mods and adjustments. Basically what I'm saying is , a stock pump with only big plungers ,will not be as good as a fully built smaller pump.
The turbo is a bit high,but the truck has a 2 inch cowl hood. I have torqued head studs at 130 or 135 ft lbs before. At 150 ft lbs the deck starts pulling up around each stud. We used a new timing chain ,that was probably made in the 90's ,and it fit very tight. The nozzles are china 311's...
Had it runing on the stand. Engine seems good,but inj pump leaks at the advance plug. Have the injectors set at 3500 psi. Ip is not putting out as much fuel as it should either. I think the advance is not working, prob because of the leak.