what is the differance between the two? and how much boost can the stock 2 v can take?
The KB 2.1L does not require a hood change, as the Tork Tech and the KB 2.6L does (this was copied from the Tork Tech website):The minute you "step up" to the higher HP numbers with a KB is where it hurts you. The pulley upgrade, the bigger injectors, the new hood to clear the new pulley set up. At least with the Tork Tech kit, you don't have to buy any additional upgrades. Everything is there to go to 600 if you want. The other thing I like is the independent belt, that only runs the blower. By increasing the crank pulley size, you can also up the boost. Yuo Tube has some good testimonials on the product from JDM, HP Ranch, etc.
Kenne Bell on a Mach 1 is killer! I have buddy's with Procharged Mach's and there is just no comparison. :bigthumbsup+1 on the KB kit. I have the intercooled 2.1L kit and abosolutely love it, the torque, the scream, the whole 9 yards. You can get over 400rwhp easily with a proper tune. Well worth the money, and KB has a pretty good name that has been around.
I bet a KB on a Mach running 10psi could make upper 400's to the wheels maybe.