aMirage, have you checked my webiste?
Soda's Aircraft Evaluations Look there for some specific tips on each aircraft.
Generally, in the case of La7 vs Spit, you should evaluate your starting positions early. The Spit, especially a Spit IX, can put on energy pretty quickly and can hold energy really well. You know the SPit's superior low speed turning will easily beat an La7. So, you need to try and merge to gain position (or energy) advantage and then keep the fight fast. Don't let it get slow on you or you will be in trouble quickly. The problem with most La7 vs Spit engagements is the Spit comes in with altitude/energy excess and can pin down an La7 and thus force the fight slower and slow (or more and more turning) which quickly favors the Spit.
On any reversal where you extend, make sure you extend enough to get your nose around and face the enemy again. This is a common mistake for newer players, they try and reverse at D2.0 and find themselves not quite able to get guns on the other guy and thus are losing angles right from the start. It's better to extend longer, D4.0+, maybe even out of icon range, then reverse. This gives you a chance to merge at least even.
Finally, it will really depends on the merge in a fight like this. You need to merge well and watch what the Spit does. If he is Co-E with you then he is likely to be able to at least match almost anything you try and thus you have to be very very careful. If you can merge to a dominant position (say by zooming higher on the merge) then you can force the situation for a while. It'll come down to timing your shots and making a snapshot on the Spit as he will likely try and break-turn and make the shots hard. Most of that is timing and knowing the La7 guns.
Hope that helps. There are lots of variables to deal with in any fight so no single description/tactic covers even half the situations.
