an eye on your suspension and steering and make sure they can both support the weight of a diesel and clear the engine itself. The lesson here is to keep an eye out for what you might need at this juncture so you’re not stuck for weeks waiting on parts.
STEP SEVEN: Cutting, Trimming & Welding
With an engine and transmission mounted and the chassis and suspension reinforced there’s still a ways to go, and this is often the most time-consuming part. Unless you’re just willing to chop up your entire car (say, a rat rod), it would probably be nice to have things like a dashboard, firewall, inner fenders, trunk and the rest of your sheet metal. Unless you’re shooting for a swap into a similarly large truck, much of the sheet metal on your vehicle will need trimming or massaging. The firewall may need to be moved back, the core support modified, or the hood may need a hole cut into it. On the inside, the pedals and steering column may not line up anymore, or the transmission tunnel could require some rehashing if a large transmission like an Allison 1000 is being used. There’s also gauges and gauge placement to think about, unless you want a lot of stuff zip-tied to other stuff.
The rear suspension doesn’t have to be super complicated for it to work. Many choose to go a simple leaf spring route, which handles power just fine.
Body swaps are another common form of swap. This Blazer actually isn’t all Blazer, but rather a Blazer body on a shortened Dodge Ram chassis. This meant the factory engine, transmission and axle were all parts designed to work with a diesel engine.
Any spare space you have in a diesel swap can be an asset. Here, Mike Racke uses the big fenders on his ’55 panel van to hide the factory Duramax computer.
A non-truck rear end can be made to work, but it’s usually not cheap, especially with slicks. Expect a fabricated housing rear like this to run upwards of $3,000.