I've located a 84 K30 diesel crewcab with a bad TH400. Thinking of building me another tow rig to replace my K5. Would like to build NV4500/205 drivetrain and power it with BB 454, 496 or 502. Never had a diesel but am attracted to fuel mileage but only if they have the power to tow. Looking at suggestions from those that know. What would you build if you could? 6.2? 6.5? Possible Cummins conversion? Tow about 5-8k lbs. of trailer. 87 K5, D60 & 14FF, 5 sp & NP208 & 383 stroker. Build it Bulletproof and take it fishing!