I recently bought an 86 Corolla GTS coupe and was wondering a little about the engines that would suit me best. There's only three that I've been looking up and wanted to get some first hand opinions on them. Right now it has the stock 4AG with 190k miles. It's pretty strong. The ones I'm looking at are the 4AGZE, 4AG 20valve, or another 4AG with less miles. I'm still going to keep the stock one in there until I get a good feel for the car but sooner or later I'm going to upgrade or atleast do some mods. Aren't they around the same price range, atleast the turbo and the 20 valve? About how much hp can I get out of them? How much of a hassle are they to swap? Can I get some feedback please.