I was going to suggest solid axle a 100 series until I read through everything. Before you start asking V8 swap or 100 series, you should make sure what is allowed since you're worried about emissions. What are the rules regarding motor swaps? Honestly though, if you kept it simpls and did the work yourself, you could probably pull off an LS swap under $8k. hell, I seen a few whole engine, trans, wiring etc... setups on CL for $700-$1000, summit sells stand alone stuff for them, advanced adapters makes adapters for most everything to a GM trans or I'm sure ignition they don't have it; Marks most likely does. I'm personally not a fan of the LS Fad, Or Cummins Fad. Hell, I'm not even that keen on my own monstrosity so far....only because it's not done anencephaly haven't had a chance to test it, but still. I would have considered a Toyota V-8 if the fuel economy and power were better. Anyway, in the end it isn't about what you want, what you need and cost .vs. benefit of each. If you want someone to make the decision for you, then I say hold onto the 80 and really go through it. New injectors, new catalytic converters, valve adjustment etc... bring it back to life that way.