planning on a new powerplant for the old girl- who is the best rebuilder with best warranty for the 93 class ohc engine?

The best warranty I found was through ATK engines (www.atkengines.com) 3 yr unlimited miles.
2nd best were included Ford/Motorcraft, amongst others, that offered 3 yr/36K miles.
FYI, Ford didn't offer an OHC engine in Explorers until '96/'97. Unless it's aftermarket, you have an OHV engine.

Do your own research. The remanufactured engine I used was by Capitol City Rebuilders, a company owned a local Ford Dealer, who remanufactured engines and transmissions for Ford, Chevy and Dodge applications. I bought the engine from NAPA.

I just got a pretty good deal, arrives today, from Better Built Engines in Rock Hill, SC 1-800-662-3644. 18mo/18k warranty. not the best warranty out there, but I only paid $1500 and that included shipping.

Roger my error on the OHV thing.

I have done my own research. However, in the format of a forum like this, you are most likely to find a firm that does a superior job at a reasonable price, if you just ask.