Overheating issues on a rebuilt 360

When you say to the left you mean counter clockwise right?
Just saying left and right or counterclockwise or clockwise ain't cutting it... put it back where it was get it running again and then slowly turn it each way to get the maximum rpm... Go to Harbor Freight and buy a $32 timing light..make sure you read the instructions carefully on how to use it. And use it...
Do some research on your timing and how to set it.. the entire tune of your car depends on it...