Before I make a mistake please help new mopar fan!!

I found a 383 that was rebuilt to stock specs the guy wants like 1500 seems alil steep considering it's been rebuilt 6 years ago and sitting I'm a garage. Where is the you pull it with the magnum 360. I ony have friendship junkyard by me and he only had one 318. I can rering a motor just don't want to have to bore untill I can do it right. I just picked up two 727 trannys today. One small block one big block from a friend who just had them sitting so I'm good either way haha