To modify this correctly, the upper control arms usually need to be shortened, and the lower control arms need to be lengthened. We also have custom lower control arms available with a length that is 1/4" longer than stock, that will increase the stock pinion angle setting by approx. 1-1/2 to 2 degrees. The custom length arms should ONLY be considered if you know exactly what your pinion angle is currently. You will need a magnetic protractor to check your current setting to see if this will benefit you

Lengthening the lowers along with shortening the uppers is better than just shortening the uppers by themselves. This will keep the driveshaft from being pushed too far forward into the transmission, and also increases tire clearance under acceleration

As stated above, the custom length control arms are designed to achieve maximum performance with higher HP cars with limited street use. If you do not know what your pinion angle is or if you drive your car a lot on the street, then the standard length arms will suit you best. The majority of benefits will be found from the design and construction of the new control arms, and not from changing the length. Too much pinion angle on a mild street car will actually reduce power and wear U-joints out faster than if left at the stock setting. Of course, everyone has a different combination and purpose for their car, so please do some reasearch or call if you need help