What is your timing set at? If it is knocking, you need to retard your timing until it goes away.. You have to be careful about accelerating with a heavy car and highway gears when the compression goes up. Heat, lean fuel mixtures, heavy loads, incorrect timing, as well as other factors combine to create conditions for knocking, or detonation. Do you know how thick your head gaskets are? As far as guessing your compression ratio based on compression test #s is hard to do as things like how fast your starter is turning will affect it. If it is knocking at cruise, your vacuum advance needs to be lessened. disconnect it until you figure out how to adjust it. When you raise compression, your engine needs LESS timing advance. Your distributor affects advance 3 ways. Where you set it, centrifugal advance, and vacuum advance. You will need to research this stuff, and how to check and adjust it. Until you get it all sorted out, retard, and disconnect the vacuum advance to stop the knocking or you will ruin your engine. I think you can get it all set up right but it will take some more time and learning......but it sounds like you are not afraid to learn, lol. Tuning and adjusting become more critical as your engine moves away from stock, and you might need to run higher octane gas.
1. set your timing with the vac advance disconnected. Set it to 10* for a starting point.
2. At idle, your vacuum advance, depending on where the hose is connected, will have either advance 0* or it will max out. Hook it to the max out spot and read your timing with your light....If it says, for example, 30*, you will know your vac advance is adding 20* because 10* and 20* equal 30. Your advance may be adjustable with an allen wrench put through the nipple your hose hooks up to. I dont remember which way to turn it to lessen it. I also dont know if your vacuum advance will have this type of adjustment, but it may. Adjust it to the least amount possible. When you hook it up, connect it to the port with 0 vacuum at idle....but dont hook it up yet.
3. Rev your engine up while measuring your timing with the light. Do not stand or put your face in line with your fan blades as they can come apart.....very rare, but it happens. measure your timing from idle up to the point it stops increasing as you rev it. You are looking for how much centrifugal advance your distributor has. Write it down. It is also adjustable, but requires taking your distributor apart and I am not getting into that now.
If you add all these numbers up, you will know how much advance your engine is getting as you cruise down the highway, and from the sound of it, you need to lessen that number.