I was cleaning up the 396 to put it into the 79 and would like some feedback. The 396 ran great before I pulled it out of the 71 fyi. The block number is 3999290 which is either 396 or 402. After pulling the intake I see that they had a square port intake on the oval port heads. I do have a BB oval port Edelbrock Air Gap intake I can put on it. The current heads are 6272292. I have a set of head on the shelf that are 3856206 that supposedly were rebuild by po and have gold aluminum roller rockers. Is it worthwhile swapping these heads or just run the way it is?