ThunderV12, LLC

Re-Birth of the
GMC 702 ci V12 Engine





ThunderV12 is a registered trademark of ThunderV12, LLC.
All rights reserved.

Welcome to ThunderV12, LLC

ThunderV12, LLC is home to the rebirth of the GMC 702 ci V12 engine. American-made V12 power! ThunderV12, LLC has a significant inventory of GMC V12 1960-1965 engine cores that we have disassembled and graded. Only a small portion of these cores are good enough to become ThunderV12 engines. Our goal is not to rebuild GMC V12 engines, but to create ThunderV12 engines.

The basis of the ThunderV12 engine is the ultra-rare GMC 702 ci V12 engine manufactured from 1960 to 1965. This engine was originally used in over-the-road semi-trucks, fire and airport trucks as well as stationary power applications.

Much time and hundreds of thousands of dollars have been spent to find, gather, manufacture parts and make available these power plants for your pleasure. Enjoy!

The ThunderV12 makes the most power between 2,000 and 3,000 RPM of any automotive-based naturally aspirated 87 octanes fuelled crate engine you can buy for under $35,000.

Rare, Unique, Powerful, and affordable!

Why we are here - Our Goal

At ThunderV12 LLC, our goal is to provide highest quality GMC V12 based engines to the hot-rodders and custom car builders who are looking for something different.
Building a hot-rod is a lot of effort and expense. With the proliferation of 75-year-old Ford bodies stuffed with small block Chevy engines, it is hard to get noticed. Stuff a ThunderV12 in the front of anything and the crowds will form!

ThunderV12, LLC


Wiki states over 90,000,000 Chevy small blocks have been produced from 1955 to today. For comparison, GMC produced less than 5,000 V-12's and we estimate less than 200 remain. Most of those 200 are basket cases. The ThunderV12 is the best of the rarest.


Shelby built Only 32 427SC Cobra's in the 60's. The 427 SC Cobras is now one of the most collectable cars on the planet easily fetching $1,000,000 at auction. Looking ahead in the world of custom cars, where will a ThunderV12 powered car be placed in history? Wish you had bought that Cobra you saw in 1975 for $4,300? Will your custom car with a V8 Chevy be accepted to the high-end car auction? Probably not. What if you had built it around a ThunderV12?

Collectability takes insight. Time is limited. The time is now.

ThunderV12, LLC is the leader and simply the best

Call Us Today!
No one can sell you a better GMC V12 engine.
Click here for pricing page.

A baby Merlin?
The GMC is a full foot shorter in height than the Rolls 1650. This becomes important when the time comes to see out the windshield!

Want to do some fun browsing? Check out our links page!

Trans options - so many

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