Alot depends on compression and what kind of ignition box you are using.
If you have a start retard like most do that lock out timeing then you are fine but if you don't and have a decent amount of compression you could have a hard time getting the car to start with out issues.
Also alot of cars have the timeing locked out because they are using a power adder which is commenly N20 and they do not want the timing to change from were it is.
I hope this helps..