I read back through a few pages and see a few guys looking for more steering.
The Tc3/4 were from a different generation of TC. Less power, less runtime, and honestly slower lap times. You can make changes to the car to make it competitive, but making spring/shock/camber rod changes wont be enough.
Make up a slipper spool. I did a writeup some pages back on how to do it. It works great and saves your driveline parts in a collision.
Once you add the spool you will have what seems like ZERO turn in. Add caster. I ran as much as 8 degrees. The Losi XS caster/steering blocks fit perfectly, widen the front out just a touch, are very durable, and give you more caster options.
Also run the Losi XS rear upright hubs. Rear grip becomes predictable and easy to drive at the limit. The car locks in on throttle and gives way as you let off.
On hot asphalt with Sorex 36-40's i would run #1 pistons front and rear with 50wt front and 40wt back. It was a great balance to start with, and work from. It is also VERY important that your shocks move flawlessly smooth. This doesnt mean you need to rebuild them a lot... it means you need to make the best of what you have. Polish the shafts. Make sure you use good seals... and LUBE THEM UP.
Shock springs? Thats always gonna be relative so there is no surefire place to start... but starting with 10lbs in the front and 25lbs in the back should compliment the above settings nicely. I used XRAY springs, HPI springs, and threw my AE springs in the trash.
And always tweak your car. You want the car to squat and shoot when you stab the throttle, and then stabilize for the next coner after passing that guy in the chicane? TWEAK THE CAR. It adds predictability and allows you to drive the piss out of it. Trust me, its a beautiful thing to throttle past a $500+ TC in the chicane, and make it stick in the exiting corner.