I have one, $100 and it's yours. No more AE86's for me, this one was a spare. Needs to change a few gaskets like oilpan/valve cover, but it's a good motor.
If you want, you could take the head off of your 4A-C motor and swap a GE head onto it, it'll be lower compression good for turbo. The only differences in the internals are lower compression and the 4A-C has 6 flywheel bolts instead of 8, but it utilizes the same clutch. You also need to swap the oil pans (4A-GE has oil cooler), the alternator, the PS pump, the crank/waterpump pulleys, and the brackets for the PS/alt. Also note the headbolts are different, the GE uses 10mm 12 point bolts and the C uses 12mm 6 pt bolts, use the GE cuz the GE head is taller, thus the headbolts are a tad longer. IDK what you wanna do, but this is a suggestion, I've done many of these due to limited supply of 4A motors when the AE86 kept blowing motors from excessive boost.
