Re: Need info for 1953 Willys Truck
If you're on a budget and do your own welding, just stuff the 304 and all in and hope for the best. BUT if you are spending any amount of $$ do it right, Go Ford!
We are finishing up a '60 Willys wagon retrofit. We are putting in a Ford 5.0 out of a '94 Mustang and a New Process 435 tranny and a NP transfer.
The next thing that you need to think about is the axles and brakes. The old axles won't stand up to much horse power and they are hard and EXPENSIVE to get parts for. The ratios are really low and you will hate it with a modern engine. The brakes on those old Jeeps really bite and are real hard to find parts for!
A front axle from an International Scout II '74 or later is a Dana 44 and will give you disc brakes up front. The old Willys trucks are extra wide in the rear, so get your rear axle from an International Travelall. It will probably be a Dana 60. These axles will probably have a ratio of 3.73, but MAKE SURE THEY ARE THE SAME!! Dana's are easy to get ring-and-pinions for. Your old wheels will bolt up (5 on 5 1/2) but won't seat correctly because of depth so toss them.
For anyone reading this who is doing a Willys Wagon, you can use the rear axle off of the Scout II.
Get the proportioning valve off of the Scout and use a Ford F100 circa 1970 master cylinder. Rebuild the disc brakes with Ford F150 calipers, circa about 1979. They are the same thing as a Scout set, but won't cost the extra bucks for the obscure reference. Get the brake and clutch pedals out of an old Ford van, around 1960, because they mount on the firewall. Reinforce the firewall.
You can mount the rear axle up pretty easily by moving the spring mounts on the axle tubes out. The front isn't quite that easy, but that leads you to some interesting options. You will have to move your spring mounts on the frame out 5/8" on each side, but that gives you a good excuse to do a shackle reversal, i.e. put the shackles in back where they give you the best on and off road response to big bumps.
Now you have to figure out the steering. A Saganaw box off of about a '72 Comaro or Firebird with 3 mounting ears has the right valve set for you, BUT get the pitman arm off of the Scout II, it's longer.
You will undoubtedly need new springs and Alcan springs are (in our shop's opinion) the best way to go for your money. You will probably need custom drive shafts now because of the increased horsepower and the new distances.
Now that you've done all that, you have to paint it nice so that people don't refer to it as an "Old POS." A really tricked out '50s Willys truck is a slick ride.
Do good work and keep in touch. Send pictures.