Brent what I think Ziggy is refering to is if you are not running a one way diff on a 4-wheel drive car that has smaller diameter tires on the front than the back it causes the front end to create drag on the drivetrain because the rollout for the front end is less that the rear, the front end is covering less distance than the rear.. The solution is simple just true the front and rear tires so they are the same height or get a oneway diff for the front end If you check out your typical 1/8 scale onroad car you will notice that the front tires are alot smaller in diameter than the rears they use a oneway diff to compensaite for the diff in diameter and create a overdrive ratio. I would not reccomend that you use 1/8 scale fronts on the rear with the stock gearing you have it may make your car have less traction . But looking at your pictures of your car the tires look like they are the same height anyway
You can get a soild rear end for your TC-3 too.