Passion To Convert

June 2015 Brady L. Kay

When we were toddlers our parents were quick to “help” us when we attempted to put the square peg in the round hole. With a gentle voice, mom would kindly let us know that you can’t just make something fit that wasn’t designed to be in that space. Luckily a lot of diesel enthusiasts failed to follow this type of logic, because if they had, there wouldn’t be such a thing as a “Fummins” today.

A Fummins is a Ford truck with a Cummins engine under the hood, and although the name is clever and simple, the task of converting or merging two vehicles together is actually a lot of work. The reasons for wanting to do something like this vary, but the most common response is the owner loved the look or style of a particular truck, but also wanted a specific engine that wasn’t designed to match.

The reason I’m attracted to conversion projects like a moth to an open flame is because there is truly an art to doing it right. I admire those skilled fabricators who can look at the tiniest amount of space and figure out how to get the most out of it. It’s not like there are manuals or how-to guides on doing this either. Only through experience and time do fabricators get to the point where they can make the task of converting or merging two vehicles together appear effortless.

Corners can be cut to save money—for example, choosing not to have every control or switch perfectly match up. However, most people who choose to do something like this are usually fully committed and will invest the time and money to assure it’s done right. It fascinates me to see just how many man hours go into these projects where custom fabrication and a lot of trial and error come into play. Some of them become side projects for busy shops, while for some businesses it means keeping your fabricator busy and unable to help with other projects for several weeks.


Often the unique build is specific to an owner’s needs and the conversion is more out of necessity than simply just a desire to have something different. For example, have you ever come across a “Duraburb” before? This is when you take a Chevy Suburban and convert it to a Duramax. Now you have the power and performance Chevy diesel owners have come to love, but with plenty of room for the whole family as well. I know a shop that is not only in the process of building a Duraburb, but actually working on creating two of them at the same time. I guess if you’re going to put in the time you might as well build them in pairs.

I’ve also seen old vintage trucks from the 50s and 60s transformed into modern day diesel beasts; the possibilities are truly endless. One of my favorite discoveries is the “CaddyMax,” which is currently at the 100-hour mark with at least 30 more hours to go. The square peg in a round hole philosophy never rang more true than on this build. In this case the owner bought an old 1970 Cadillac and took it to Adrenaline Performance in Shelley, Idaho, which has several conversions under its belt as a diesel performance shop. I’m positive that when this Caddy first rolled off the Detroit assembly line no one there was thinking about the possibilities of stuffing a twin turbo LLY engine into it in the future. For one, the 2005 Duramax was years from even being released. But for Garth Hall, a man who is passionate about Cadillacs and loves his 6.4L daily driver Power Stroke the time and money spent to create the very unique CaddyMax was well worth it and it’s getting closer every day to being complete.

What conversions have you seen or would you like to see if you had the money? Jump on our Facebook page for Diesel Tech magazine and let us know. We’d love to hear from you. 

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