anyone ever replaced the heater hoses [from the heater core to the engine] and not used the factory stuff. i wanted to get see if someone has already done this and the install works well and looks clean. figured the original [nearly 30 years old] hoses are due.

I've used aftermarket orange/red color stuff. It works well and I don't think detracts from the look. I don't see why using any aftermarket hose would be a problem.