The “big-block swap” has always been a treasured hot-rod tradition. The most memorable was at Wally Baynes’ Los Angeles garage, where a 1957 Ford Ranchero was given the 365-cubic-inch (5.9-liter) 1956 Cadillac V8 in place of the 292-cubic-inch (4.8-liter) Ford V8 that came from the factory. The Cadillac upgrade promised a much more powerful, smoother-running machine that still kept the Ranchero’s traditional looks.

The mix of components from Ford and Cadillac had to be engineered to work in close proximity in several spots, including around the chassis crossmember, steering linkage, oil pan, starter motor, transmission, and engine mounts. Baynes overcame these obstacles with unique fabrication, utilizing a mix of vintage parts and new manufacturing. The results showed that a radically different powertrain could be installed without hacking up the body or chassis.

1. Swapping the Stock Ford 292 V8 for a 365-Cubic-Inch Cadillac Engine

As awesome as the factory Ford 292-cid V8 was, a Cadillac 365-cid V8 is a far more powerful and higher-tech engine. Admittedly, Cadillac’s overhead-valve design is a far cry from the Ford’s cast-iron and flathead architecture, but it is just as smooth and just as torquey, with the added bonus of being just a little more discreet than the cast-iron Ford piece. All of this translates into a Cadillac big block making a great candidate for a simple swap and installation that would go largely unnoticed. You could sell the early Ford engine on the swapper market.

Cadillac V8 Swap:

• Original Ford 292 V8 removed
• Cadillac 365-cubic-inch engine installed
• Greater torque and smoother operation
• Original exterior appearance remained unchanged
• Removed Ford engine helped offset costs

which would help compensate for the cost of the Cadillac engine, and the widened engine bay could be worked around with some careful headwork.Integral to the installation was whether the Cadillac V8 could be integrated into a chassis built for other mechanical configurations. Rather than making a number of largely visible modifications, Baynes concentrated on the fabricating up-front where the two makes’ components were different. The result was a car where you could have the roaring V8 under the bonnet and the familiar dimensions of a Ford Ranchero.

2. Sectioning the Oil Pan and Reconfiguring the Oil Pump Pickup

The Ford chassis created a significant obstruction under the engine as its tubular crossmember and steering linkage restricted the space required by the Cadillac oil pan. The factory original Ford engine’s sump was located in the front of the crossmember, but the Cadillac V8’s sump was in the back. The sump locations clashed and the Cadillac engine wouldn’t clear the crossmember so it could sit where it belonged. Baynes started by removing the vane-type vacuum boost pump that was bolted to the Cadillac oil pump.

Oil Pan Modification:

• Ford crossmember restricted sump clearance
• Cadillac engine used rear sump
• Vacuum boost pump was removed
• Oil pan shortened by 1.5 inches
• Oil pickup tube extended forward

By eliminating the vacuum boost pump we were able to eliminate about 1.5″ in height in the sump portion of the Cadillac pan which made for a much shallower pan. We ended up mounting the engine roughly an inch higher in order to clear the steering linkage. In order to retain a good oil capacity we welded the front part of a Ford oil pan in place in front of the crossmember in the Cadillac pan, and then extended the oil pump pickup tube to the new sump to make the oiling setup work in the Ford chassis.

3. Adapting the Starter Motor and Bell Housing Connections

The oil pan was not the only thing that interfered with the Ford chassis. Because the standard 1956 Cadillac starter motor was simply too long to accommodate the tubular crossmember, a different starter was needed. Baynes ended up using a 1957 Cadillac starter that was a tad shorter overall and cleared the crossmember. But this set the stage for still more problems, because the starter’s mounting pattern did not match up with the starter’s bell housing pattern.

Starter Motor Adaptation:

• Original starter contacted the crossmember
• Shorter 1957 Cadillac starter selected
• Starter mounting holes required modification
• 1955 Cadillac bell housing adapted
• Allen-head screws secured the starter

Here’s the trick to securing the replacement starter Baynes drilled the threaded starter-mounting holes all the way through the bellhousing so that the housing was mounted from the back with Allen-head cap screws. This adapter fit the mixed starter dimensions, provided a solid way to attach the unit, and preserved the Cadillac parts without having to ditch them completely-another example of an easy, small change that can be made in an engine-swap engine mounts conversions to make things fit.

4. Crafting a Custom Crankshaft Pilot Bearing Adaptor

When mating the Cadillac engine to the selected transmission, crankshaft and transmission-shaft alignment had to be considered. The Cadillac crankshaft did not have a bore at the end of the crank for insertion of a pilot bearing, a stumbling block for any transmission combination that uses a supported pilot shaft. Without a mounting point, the shaft cannot be mounted and supported as it was designed. An adaptor was required to compensate for the Cadillac crankshaft design.

Pilot Bearing Adaptation: 

• Cadillac crankshaft lacked pilot bore
• Transmission shaft needed proper alignment
• Custom steel adaptor was machined
• Adaptor press-fitted into crankshaft flange
• Pilot shaft shortened by 1/4 inch

Baynes machined a steel adapter which was designed to be press-fit into the rear flange of the Cadillac crankshaft. The adaptor was used to hold a standard Hydra-Matic pilot bushing which provided the mounting point needed for the transmission layout. Due to the extra adaptor depth, about 1/4 inch was shaved off the nose of the transmission pilot shaft to maintain the proper depth and alignment of the setup.

5. Adapting the Hydra-Matic Transmission and Fabricating Frame Mounts

A matching transmission was necessary to match the new Cadillac V8. Baynes chose a modified 1953 Cadillac Hydra-Matic assembled by Transmission Specialists in Los Angeles. If it were available, a 1954-55 Cadillac or Chevrolet truck Hydra-Matic could be adapted without any additional modifications, because of their shorter main-drive and torus-member shafts. The assembly also required an appropriate flywheel, such as a 1954 or 1955 Cadillac piece, or a 1954-56 Oldsmobile flywheel with one bolt-hole elongated.

Transmission and Mounting: 

• Reworked 1953 Cadillac Hydra-Matic selected
• Compatible 1954–55 units were alternatives
• Suitable Cadillac or Oldsmobile flywheel fitted
• New front mounts fabricated from steel
• Rear transmission support required custom bracket

Because the powertrain mounts were a new design, the original Ford front engine brackets could not be used in their current locations. Baynes cut them off the tubular crossmember with an acetylene torch and made new mounts from quarter-inch steel plate. Once the engine was in position and the mounts tack-welded to the frame rails, the mounts were removed so the frame and engine could be fully welded. Use of Cadillac engine brackets and insulators provided the front support. At the rear, a longer bracket was made from a 3/16-inch steel plate on the Ford center crossmember under the Hydra-Matic; the bracket supported the transmission via an H-M insulator, and the Ford handbrake lever pivot had to be moved slightly.

6. Shortening the Driveshaft and Grafting the Cadillac Flange

The new powertrain configuration placed the transmission further from the Ford rear end, which necessitated a lengthening of the original driveshaft. Instead of purchasing a new shaft, Baynes shortened the existing Ford shaft by about 2½ inches. This allowed him to adapt the stock shaft to the Cadillac transmission, compensating for the change in the powertrain arrangement.

Driveshaft Modification:

• Original Ford driveshaft retained
• Driveshaft shortened by 2.5 inches
• Cadillac flange grafted onto Ford shaft
• Transmission connection adapted to fit
• Early Hydra-Matic units preferred

The second half of the transmission link-up involved grafting the Cadillac driveshaft flange directly onto the shortened Ford shaft. Early transmission-model Hydra-Matic transmissions built pre-56 were used to achieve a good positive lock-up for the drive. The Cadillac transmission further simplified the job of fitting to the custom fabricated bracket attached to the Ford centre crossmember as it had a rear mounted tailshaft assembly. This dramatically changed the original Ford driveline to match the new powertrain as no complete new system was needed.

7. Modifying Floor Pan Clearances and Reworking Exhaust Routing

The details. The extra room that the Hydra-Matic demanded in the Ranchero imposed somewhat of a problem. The valve body and control levers of the Hydra-Matic and all of the linkages that go along with it need much more room than the original Ford layout left in the factory floor pan. So a section of the pan was cut out to make room, then to seal the opening but at the same time leave access to it.

Floor Pan and Exhaust: 

• Hydra-Matic required extra floor clearance
• Section of floor pan removed
• Aluminum panel covered modified opening
• Cadillac exhaust manifolds mostly cleared chassis
• Minor flange and firewall adjustments needed

Aluminum sheet was hammered to shape and bolted into place. Installing the exhaust was much simpler than the oil pan and tranny work. The Cadillac exhaust manifolds fit well, coming within an inch or two of all of the chassis parts in the engine bay. Only the right manifold had to be slightly relieved at the flange, and a small dent was formed in the firewall where the head pipe was attached to allow a clear path for the rest of the plumbing.

8. Setting Up Accessories, Radiator Fitment, and Final Engine Assembly

Enclosure of the engine bay entailed a number of modifications to accommodate the Cadillac engine’s location and the limited fender well clearance. Since the engine sat about an inch higher than the Ford it replaced, the production generator bracket was unusable. Baynes made up a new bracket that placed the generator below two cylinder-head bolts on the left side of the Cadillac engine, thus clearing the front fender. To provide hood clearance, a low-profile Studebaker air cleaner with an offset oil bath was adapted for use with the Cadillac carburetor.

Final Installation:

• Custom generator bracket fabricated
• Higher engine position affected clearance
• Studebaker air cleaner adapted
• Original Ford radiator retained
• Ford fan fitted Cadillac water pump

It was an even easier project to set up the cooling system. The factory ford radiator stayed in its original position, with no changes in the size of the radiator or hose. Even the factory Ford fan bolted right on to the water-pump shaft on the Cadillac without requiring any modifications. These details were important in keeping the final install clean, simple, and easy. The whole job was left without having to cut anything outside of the body or chassis for the Ranchero to retain its factory look while having the Cadillac engine’s larger displacement and smooth power.