It sounds like it has the overdrive adapter. Honestly it would be better with the GM auto 4l60e/700r4 or Manual GM NV4500 or even h55f but its better than just the stock 4spd. I would say anywhere from 7-12k depending if it is smog legal and all the loose ends of the swap are tied up. FJ60s are pretty common so the v8 will most likely boost the value a bit. The only all original ones worth more are extremely low mile, perfect paint/interior. Pretty much unless it looks like it just rolled off the factory floor its not going to be worth more than something tastefully modified.
That engine was done properly...looks really nice and detail oriented. Take the silly nerfs and rear tail light damage multipliers off and add sliders and that's a 10K truck. (If the rear wheel wells are rust free)