Thanks for the input!
My idea definetly involved a compression increase by using a mid 60's set of 383 closed chamber heads with some work done. I know the stock 400 compression is to low for sure. I figure with 9.5.1 or so compression and a good cam, it would run pretty good. I think stock compression is like 8.2...
On the flip side, a 360 with Magnum heads and a good cam will make some killer horsepower without much else done to it. My '69 is already setup for a small block and I have an extra 360 laying here torn down. I also have a 400 but I really have not tore into it to see the condition. I am going for the use what I have approach. The 360 in the car now is a stock '74 in ok condition.