How does my classic car LS swap affect transmission alignment
Proper support of the transmission after an LS Swap is a key consideration
Motorsports enthusiasts are never at a loss for ways to enrich the sport. From simple shine and go additions, to performance improvements, one's imagination is the only boundary. An old school power-plant stuffed into a late model chassis, or a modern engine and drivetrain transplanted into an old school classic iron chassis, the enjoyment of the accomplishment pushes the "motorsports junkie" from one project to the next.
The popularity of the GM LS engine has brought forth a huge demand for LS based performance products, as well as components to aid in swapping the electronically controlled powertrain. One of the most overlooked aspects of an LS engine conversion in an older muscle or classic car is supporting the transmission end of the new powertrain. You can read more about Transmission Swap Basics here.
Various motor mount adapters for an LS conversion are commonly designed to allow positioning the engine at the stock bellhousing location, or forward by 1 or 2 inches. Moving the LS engine forward is often required to provide clearance of the cylinder heads and the exhaust headers to the firewall and other chassis components. Combine this with an electronic shift transmission of various size and configuration options, and the transmission mount is no longer positioned over your transmission crossmember.
The G Force Performance adjustable LS motor mount adapter set allows the installation of a LS engine into early model GM vehicles that utilize a standard 3-bolt style motor mount. The mounts are adjustable to position the bellhousing in the original factory location, 1" forward, or 2" forward positions. A feature that is unique to the G Force Performance adapter is that the 3 locations are geometrically positioned to facilitate retention of proper driveline alignment, regardless of stock or forward position. Additionally, within each position is 1/2" of infinite adjustment for greater positioning flexibility.
A G Force Performance transmission crossmember is, (unless noted), designed for OEM, or stock bellhousing location. For example: You are bolting a 4L80E transmission behind your Big Block Chevy in your 69 Camaro; the G Force Performance transmission crossmember for that application is based on the bellhousing positioned at the stock location behind the BBC. Find out why our customers choose a G Force Crossmember here.
Variables such as an LS swap that relocate the bellhousing location must then be addressed. This can be done in some vehicles by moving the crossmember the required 1 or 2 inches
and drilling new holes. Another option is the G Force Performance adjustable transmission mount. This mount allows the crossmember to remain in the stock location, with the mount adjustable forward between 1" and 2- 1/2".
In the broad scope of an LS swap, these are just a few of the aspects to consider. But a little advanced consideration and foresight as you consider your component purchases will go a long way towards making your conversion simple and fun.
For more information about LS swaps, check these blog articles: