General Motors LS Swap

Since Mercedes are traditionally a luxury brand, moving all that weight requires torque. Historically, a lot of the Mercedes bodies therefore have had to accommodate large displacement V8s. This makes it a natural candidate for the ever popular GM LS platform swap.

LS engines include the original LS1 (5.7L) as well as the subsequent LS2 (6.0L), LS3 (6.2L), LS6 (5.7L), LS7 (7.0L) and LS9 (6.2L S\C) blocks, which are all aluminum performance application that are generally debuted on the Corvette. These are all in high demand and command a fair dollar on the used market.

While not exactly LSX series, the LS-based Vortec engines are similar to their brethren, but are designed for heavy duty applications. They are generally iron-block with aluminum heads, under-stressed and emphasize a bottom end torque. They are generally roughly 100lbs heavier but are quite durable and end up getting used in forced-induction applications for that reason. These were produced in massive runs and started the original LS-swap craze due to being readily available in scrap yards. The most popular offerings are LM7 (5.3L), LR4 (4.8L) and LQ4 (6.0L). 

There exist numerous documented LS swaps in the Mercedes community. We have seen them in W124, W126, W201, W203, W210, W211 and W212 and probably a lot more. The FR sedan layout in these platforms enables just the right amount of room in the engine bay to fit a typical LS engine.

For anyone handy with a TIG or a MIG, fabricating engine mounts is going to be quite straightforward. There are a number of DIY LS engine mount kits on the market that will make this task even simple, such as:

Notice the slotted engine plates, these allow for a fair bit of front-to-back adjustment and us a great bit of flexibility to have. Alternatively, you can take existing swap mounts like the Dirty Dingo 300Z swap mounts and modify them or the cross-member to bolt up to your desired motor position. If you do this, you will end up having to vertical space these up (large aluminum round stock works well). Additionally, I recommend increasing the size of the main mounting bolts to an M8 or an M10 in Class 12.9:

Chances are your LS or Vortec engine came with a rear sump and like many other swaps (including the Nissan S-chassis), you will need to convert to a front sump to clear the cross-member. Luckily, the Pontiac GTO came configured this way from the factory, so this conversion consists primarily of factory GM part numbers. This is a good chance to consider upgrading the oil pump, Melling offers higher flow variants. Additionally, a Canton Racing part number listed below can act as a performance upgrade, reducing chances of oil starvation as it comes with a 4 way check-valve-flap baffle for the pickup (and giving you more vertical ground clearance):

The following are useful considerations for the W210 platform, as configured by me on the Dapper Drift V2 build but may apply to others. 

Seemingly one of the best options for a manual gearbox in swaps is what the fifth-generation Chevrolet Camaro SS (V8 LS) came with: a Tremec TR6060. With some very minor modifications to the W210 tunnel (Can’t Touch This) and cut-off wheel action on the transmission body (connector protection stand outs), the engine and the transmission combo fits beautifully. 

For the transmission mount, the factory W210 transmission cross-member can be notched and drilled to accept the Camaro rubber-bushing adapter.