Not a problem at all if you are only switching the block and re-using the 88(RENIX) head. You can use the HO head but it will not line up correctly with the ports on the 88 intake. You will have to use the 88 intake/exhaust/injecters, accessory brackets, flex plate, distributer, valve cover and all of the RENIX sensors and outputs.
I have not done the closed to open as I don't see any real gains if the coolant system is properly maintained, but I'm sure that there is a write up somewhere on here.
I would have the RENIX head rebuilt and then use it with the HO block. If your valve guides are good, a machine shop should only charge around $150 to clean, mill, then regrind and lap the valves. I would also replace the rockers/fulcrums and push rods, about another $100.
Thats my $.02, others may have other opinions.
