What 727 is this?

Thanks guys, my first big block. Did not know what it was or if it would fit. Answered Craigslist add for 37 plymouth coupe last sat afternoon that was rat Rod,roof cut off turned conv. Had fresh 383 with trans ,mopar performance valve covers in the box,m1 intake new plus lots more.1500 Or best offer. Add was up for an hour when I saw it,offered 1200 he said yes. 200 miles one way. Did not really want the car but has maybe aspen or diplomat front end grafted on with discs and a 8 3/4. Nwdart