WATCH: LS4 King Announces a Moroso Manufactured Oil Pan for LS4 Engines

If there is one segment of the LSx community that gets neglected, it’s the LS4 crowd. Partly because of its smaller displacement and active fuel management, but mostly because of its front-wheel drive, transverse-mounted design. What many don’t realize, is that most aftermarket components for traditional LS-series tenges, carries over to the LS4.

That being said, there are a few unique weak point of the LS4 platform, that our friends at LS4King are addressing.

Official Release:

LS4 King Announces a Moroso Manufactured Oil Pan for LS4 Engines

So when using the LS4 in a swap, the major limiting factor are the available transmission options. The LS4 has no provision for a starter, as the starter is integrated into the bellhousing of the 4T65E-HD  — which is also specific to the LS4. This obviously can make the swap very obnoxious as you are limited to the weak 4T65 (and not just ANY 4T65… it MUST be the original LS4 (HD- Heavy Duty) application trans case which usually calls for a premium at the salvage yards).

My solution to this problem has always been to relocate the starter to the engine oil pan which effectively allows me to bolt up any transmission I choose with the small metric GM bellhousing pattern, therefore opening us up to endless possibilities such as Getrag manual transmissions, the 4T80e, the 6T75, etc. While it worked, it was extremely time consuming to fabricate and somewhat crude. It resulted in the loss of about a half quart capacity.

I have been developing a more “production” based solution for well over a year. I finally settled on working with Moroso, and we teamed up to bring the pan to market. This is a collaborative piece where Moroso took my design and significantly improved it. In addition to the redesign, they actually source some of the build components from me in the form of the machined starter stand which gets welded into the pan. These pans are made exclusively for LS4King, and will only be available through They will not be available through Moroso.

In addition to having a provision to relocate the starter, this oil pan is just a huge improvement over the OEM design. The factory LS4 oil pan has no baffles at all, it just has a big open sump. Moroso took the extra step to create a diamond shape trap door oil baffle which greatly increases oil control. The capacity was also slightly increased to almost 7-qts.

Every pan comes with a high-flow pick up tube and a spin-on oil filter adapter. Customers will have the option for a remote mount oil filter adapter as well. The pan also features a -10AN female O-Ring fitting between the 3-4 main caps which can be utilized as a oil return for turbo applications.

The pans were designed with the primary objective of relocating the starter, however any serious LS4 enthusiast should consider the pan. Even if they are using a stock transmission, this pan offers far superior oil control under acceleration and braking than is available with the OEM pan. This might be especially attractive to the Fiero swap enthusiasts.

While the oil pan was designed for the FWD enthusiasts, this would also allow the LS4 to be used in RWD applications where there is adequate subframe clearance. While in most cases it would be more economical to start with a RWD block, this does still open up users to more possibilities.

This oil pan would also serve useful for any LS swap enthusiast that needs a more “center sump” style design as it will work on ANY production LS engine block.

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