Here...I did it FOR YOU !
http://www.cygnusx1.net/supra/librar.../em/EM_09.html
http://www.cygnusx1.net/supra/librar.../em/EM_32.html
NOW...I gave you the site to the BIBLE of supras in my prior post...here are a couple of the pages that answer your questions. SO READ IT !!
You said you have experience with 20R (22R) 4 cylinder engines. 7M is different, but primarily in the head. Bottom ends on 95% gasoline engines are the same.
So we here in cyber space can not tell you if its ok to drive the car home.
Check out the 'buying a supra' thread in the FAQs section before buying any car.