360 into 64

I have a mild 360 in my car for about 1 1/2 years and 3500 miles now. I have the stock 273 manifolds on mine, and have had no issues. Just like the guys have said, you have to do a little grinding on the boss under the #7 cylinder port. I found out about that after I had the engine in. I have been told that there is about 25-30 hp to be gained by using headers. unless I was racing the car, I wouldn't bother with headers.