TCI Trans-Scat valve body kits offer you two options: you can either have good, solid shifting that's well suited to towing, or you can have competition-style shifting. These kits eliminate slippage and lag, improve fuel economy, extend clutch life, and really improve the 2nd and 3rd gear shifts. In addition to delivering crisper shifting, they allow you to downshift on demand, and most will allow you to hold first gear for extended periods, such as when climbing long hills while towing. All kits give you the full range of normal automatic functions when in "drive."