Not hard. The heads would be a swirl port on the 89's, kind of desirable. As would be the tbi.
But you have the opportunity to rip out a whole bunch of emmissions hoses and crap if you go with a carb.
IMHO if I was to do it again, I would go with a big block swap. Would have cost me roughly the same.
I went with a 78 360 into a 85 that had a 225. I went all out on the engine though. It gets better mileage than my ford v10 driving in town.
Looking to buy some dolphin meat. Please PM with offers.