Can I use hose from autoparts store or do I have to use oem for the three heater core hoses under dash? What are the ID/OD of them. Couldn't find in search.

Try www.victoriabritish.com or www.zcarparts.com. They carry replacement heater hoses.

I kind of figured it might be a Z specific part. This started out chasing a brake light short Now dash is out, seats are out , carpets out. Managed to fix a whole bunch of stuff from p.o. recovering seats as long as they are out. I guess I got caught up in the while I'm at it moment.

Most auto parts stores carry special heater hose with molded in bends and curves such as the ones needed for the heater core tubing. Just ask for the necessary curves such as the 180 degree curved tube and the 90 degree angled tube. I could be wrong though, but depending on the shop, they might have what you need.

got the 2 longer hoses going into the engine compartment from MSA, inlet $8.57, outlet $9.68 (engine compartment reducer hose about $2.40). the small pre-bent heater core to control valve hose (MSA wanted $18) was picked up from local parts store. counter guy matched bend, just had to cut to length ($5-$6).