Opinions on preliminary tune welcome----
leave a 6.5 power valve in it.
Below is one of the things I would do.
SETTING TIMING CURVE
Before you start driving it normally, I would set the timing curve so it is optimum for your particular setup . Below is just one way to do that . In general, the goal is to run as much timing as possible without it pinging under heavy load.
The more timing you have, the more vacuum it will have until the timing reaches its optimum level.
The more vacuum it has, the smother it will idle and the more you can close the butterflies.
If the butterflies are too far open, you will be into the transition circuit of the carb which can cause idle problems . One of the indicators that the butterflies are too far open at idle is when the carb has vacuum at the ported vacuum port.
1. Disconnect and plug the vacuum hoses to the dist if you have any and leave them plugged permanently or until further notice.
2. Reduce idle as much as possible then start your timing at 10 degrees BTDC.
3. With the engine warm and idling, advance the timing 4 degrees . Listen for a slight but noticeable increase in rpm and irregular/rough running . Also use a tach or vacuum gauge if you have one.
4. If the rpm increases and it still runs smoothly, reset the idle speed then increase the timing 2 more degrees and check for the same things.
5. Retard timing back to 10 degrees btdc.
6. Reset the idle speed.
7. Increase the rpm to around 2000 then advance the timing 4 degrees . Listen for an increase in rpm and irregular/rough running.
8. If the rpm increases and it still runs smoothly, reset the engine speed to 2000 rpm then increase the timing 2 more degrees and check for the same things.
POST RESULTS
TEST DRIVING
After setting the timing curve you can do the following test to see if you have too much advance.
Get the engine up to operating temp.
Drive at around 20 mph in second gear for a few seconds then floor the gas pedal as fast as you can until you reach around 30 mph and listen for even the faintest pinging sound coming from the engine . If it pings, you have too much timing for the octane gas you are using . You can either reduce the timing some or use a higher octane . The highest timing level you can run without it pinging and/or running erratic will SAFELY provide the most power.
It may ping in hot weather even if it does not in cold weather . If you find this to be the case, the easiest thing to do is reduce the timing until it stops or try higher octane gas . If it still pings with the highest octane gas, you can reduce the timing then.