You will want to set the car up so that it is like at 4.5 at the ends and 3.5 at the rear pivot (main chassis). In our Speed Spec class (mabucci motors and 21.5 motors) when we start people out, we have the springs backed all the way out. This will make the car a little pushy, but very easy to drive. In the Speed Spec class we only have them dope the center third of the rear tire and 1/4 to 1/2 the front tire (pink rears, purple fronts).
Now, if you will be running a faster motor than a 21.5 or silver can motor (17.5 or 27t), you may want to adjust that a little. I would still start with the springs backed out for a few packs, just to get used to the chassis and to get things tuned in. However, you can add more dope to the tires: full rear, half front to start, and dope more or less from there. If you are crazy enough to go straight to the 13.5, put traction compound full front and rear, springs backed out.
After you have driven the car a couple of packs and it is pushing badly, start to tune with the springs. At first, bring the springs down equally half way. The easiest way to check where the springs are is to lift one front wheel off your pit board and note what height it is at before the opposite wheel lifts. Repeat for the other side, the height should be the same.
If the car still pushes badly, bring the springs down further. Like half the distance from where they are now to the link. All we are looking to do is eliminate the push, and keep the car easy to drive. You will only have to worry about tweak if the springs are fully in contact with the links. There are many people that think that the springs have to touch for the car to be right. However, if there is preload on the springs, they will need to have equal pressure, otherwise the car will be darty and hard to drive (pssst... I was told that one of the nationals winning 12th chassis had the springs backed off 1/4 to 1/2 turn at the nats).
The Speed Spec II was designed as a spec class racing chassis with certain criteria. We have a class of them at RCE that has over 20 cars in the class, if they would all show up in one night... We hit the 15 racer mark the other night, never mind that it is the middle of summer, and it's hot and sticky and humid inside with no additional air flow. It is that fun that people show up to race that class.
If you aren't running with other Speed Spec racers and need to run a hot motor like 13.5 or more, Speed Merchant was working on putting a conversion kit together to convert these chassis to a sport World GT chassis. It would allow the use of damper tubes, which we have found to be needless with the silver can motors..