What's it worth
 

68 Chevy v8 4x4 dual wheels, what it worth

Re: What's it worth
 

Lots of questions remain to answer that with any degree of accuracy. Here are my thoughts:

IF (big if) the cab is solid, it has a good title....

Original K20: about $3500-$4800
Original C20 frame swap: about $2500-$4000
73+ frame swap: about $2000-$3000 (note front bumper is a 73+)
Napco conv: $4000-$5500 (but pretty sure it's not one)

That's just my 2 cents. If you could get it near the low end of any of those brackets and you have a need for a dually, then might be worthwhile.

I'd say best case is if it's an original K20. If body is less than decent, chop $1k off any of those estimates, minimum.