I am in the start of a build. I have posted before about my 1500 I have a 4bd1t in. I run that everyday to work. 30 psi boost. Hx30 turbo. Fuel screw and rack limiter backed out but I am now starting another build with one for a 1999 suburban. I bought two 4bd1t engines one a 1992 the other like a 1986 I believe.Both need work. The one in my truck is a 89 model. I love these engines. I am a diesel mechanic by trade. I hope and plan to build this engine even better With a bigger custom hx30 turbo, colt custom cam, head studs etc. A question I had . I priced Isuzu parts for them as well as aftermarket parts. Are the aftermarket any good As far as engine liners etc? Izuzu quit making sleeves for these engines. I just checked. Thanks