See what people are saying about Sonnax Performance Packs:
Sonnax really nailed it with this kit."
Owner of Level 10 Transmissions, after ordering his 20th Sonnax 4L60E Performance Pack.
The Performance Pack works like a dream."
Speed Rated Motorsports
Fort Pierce, Fla.
The best working performance units we have done, and that's not from me, but my customers."
Advanced Transmission Care
In a nutshell, I love it. It shifts exactly like I think it should. Not too hard, not too soft. Harder acceleration and the shifts firm up nicely."
Lindsay Transmission Service