What horse power do you think

Timing should be 34 - 36 total over 2500 RPM.

I'm assuming 18 is initial timing. Get a hold of an advance timing light were you have a knob to find the timing at different RPM's. What is your initial timing RPM? This also affects performance and you have to dial it in to make the car responsive.

total timing is where you get spark knock for whatever octane gas is run for a particular engine and compression. If it knocks you have to keep backing it off a couple of degrees intil the knock goes away. Turn the idle screw up to 2000 - 2500 RPM to check the total timing and then back it off to your regular idle rpm when done.

With an advance timing light you can check the timing at idle then see where it is until you reach total RPM. This helps you find what curve works well with your engine and how different springs affect the curve until you find the best one for your engine.

You have to figure out if you want/need to run vacuum advance or not. This will affect your setting for initial timing and how responsive the engine is.