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40 Willys Frame Plans


1937- 1942 Willys cars and trucks, street or drag car, gasser or rat rod.



The plans with work with a straight axle or a Mustang II front end.

The rear end can be mounted with ladder bars, 4 link, 4 bar or leaf springs.

Drawings are provided for a stock width frame and a narrowed version to permit you to mount monster tires and install wheel tubs.


The drawing package includes: Fourteen (14) big 11x17” pages showing you how make all parts, assemble them and then install the finished product successfully on your car. In addition to the drawings listed below you also will receive Full installation instructions, bill of materials as well as important information on how to make the options you choose work for your car. The frames shown on the right of this page are the CAD models we developed to make these plans.


  • Narrowed rear end Pro street frame
  • Stock width frame
  • Can be used with Mustang II or straight axle
  • All frame rail parts
  • Crossmembers
  • Front spring mounts (required if using a straight axle)
  • Rear coil over crossmember & mounts
  • Driveshaft loop
  • Front crossmember to mount for 4 bar, 4 link or ladder bar rear suspension
  • Layout of you work surface
  • Body mounts


This is the biggest and most complete set of plans we have produced to date. Fourteen (14) big 11x17” pages with3D viewsof all parts and assemblies to make fabrication and installation easier than ever.


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$16.99 each Willys frame plans 37-42
Item # 20


No questions asked money back guarantee.

In the unlikely event that you are not happy for any reason with the plans you have purchased please return the plans within 14 days and we will refund your money. No questions asked.


A small fee to help cover part of the shipping cost will be added at checkout.

$0.95 to the USA and Canada

$1.95 to International customers.




The plans will permit you to make a brand new Willys frame from common steel tubing. The finished frame will be much stronger than the factory frame and will hold up to today’s highway speeds. The drawings have been designed to work with the other plans from to permit the builder to install the type of front and rear suspension they desire. The stock Willys frames were an open channel (i.e. not boxed) design that are constantly flexing. The frame rails had a very small cross section and provided little strength. The small cross section and flexing resulted in a large number of these frames cracking just forward of the firewall after a few years of use.  To state the obvious any frame you may find are over 70 years old and likely have been damaged by rust over the years. It is my opinion that even a boxed stock Willys frame is marginal for today’s engines. If you are using a fiberglass car the boxed stock frame drops from marginal to not at all acceptable. The stock frames do flex and fiberglass will not take the flexing. You will soon find cracks appearing in your nice new paint job and the next thing you know the doors just do not seem to close right anymore. Do it right the first time and install a new tube frame under your Willys.

A bit of history FYI

The 1933 to 1936 Willys cars had been known as the model 77. For 1937 they were designated “model 37” and then “model 38” in 1938. For 1939 they sold both a “model 48” and a “Willys Overland 39” 1940 , 1941 , 1942 saw the “Americar” nameplate applied to the updated sheetmetal.

The 1937 to 1942 Willys cars and trucks shared a great deal of interchangeable parts. Most of the early coupes converted to hot rods or race cars now sport the more popular 1940 or 1941 front sheet metal.

Think about this. You could have purchased a brand new steel 1940 Willys coupe for less than the $599. list price. If you only could have had grandpa put away a few of them you would be a very rich man today.

The wheelbase of the cars started at 100” in 1937 and grew to 102 in 1939 and then to 104 in 1941. The fiberglass replica bodies tend to favor the 102” dimension but some were molded from other years of cars and use a different wheelbase.

The plans will work with any of the bodies and the frame can accommodate a wheel base of 100-104”.

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$16.99 each Willys frame plans 37-42
Item # 20

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