Installing a V8 Into 1947 - 1953 Chevy Truck, Suburban, Panel Truck

Article Author
Pat Ganahl
Article Revision
Thanks to Street Rodding Magazine for the instructions.
Elapse Time
1 weekend
Required Tools
  • Rachet/Various Wrenches
  • V8 Conversion Engine Crossmember
  • Modern Transmission Conversion Crossmember
  • Saginaw Steering Conversion Kit
  • Welding Unit

Many of us have are tired of shifting through gears or tapping out that old straight six at 55 mph on the freeways (sometimes on the side streets). With poor fuel economy, stop & go traffic overheating problems & certain engine parts being more difficult to get a hold of these days...converting to a V-8 is a must for a daily driver. Rear end only changes are also a good option, but not the ultimate solution for stop and go traffic. Remember, the entire drive train must be swapped out, including the rear end when converting to a V-8. The reason being is due to the fact that the most pre 1954 year trucks had a closed drive shaft. Since late 1954, most light and medium weight trucks have an open drive shaft.

Even though they didn't do it, I highly suggest removing the front grille completely. Possibly the radiator & support. Don't move them to far away from the truck though. Once you test position the engine it using the engine dollie, you will need to put them back in temporarily to check the clearance. It's easiest to get the engine into the compartment and position it this way. Although, in this article, they didn't remove the grille, they did remove the hood for easier installation.
To get clearance for the automatic tranny under the truck's flat floor, we cut the center of the stock crossmember, welded on 1/4" plate brace & formed new transmission mounts. The mounting lowered the transmission 3" & moved it forward 3". It would simply bolt right into the stock location, this is part of the reason this was done. Today, this is not necessary. This article was written in 1977, before aftermarket crossmembers where available. Most of the aftermarket truck part stores (i.e. Brothers, Chevy Duty, LMC Truck, etc.) carry both the engine and transmission crossmembers with mounts. This step, & the next two steps, can be skipped unless you really want to test your metal fabrication skills.
Saddle or craddle-type tubular engine crossmember was cut to fit between the frame rails, pieces of 1/4" plate welded on the ends, then positioned & drilled for bolting to the frame. This way the engine can be positioned in the truck and saves time with teatius measurements. It's best to use side engine mounts verse the earlier front engine mounts. This will help relieve undue stress on the bellhousing.
The stock bellhousing crossmember must be cut away (arrow). Thus, crossmember engine mount is preferable.
There is only one real problem in the whole conversion process, the steering box. The steering box must be moved 1-1/2" to the left. We used a 1/4" plate & two small tube spacers. Moving the steering box too much would alter the steering geometry, so we kept it as tight as possible.
The 1/4" plate is welded to the top of the frame rail. The steering box bolts to it & through the two small tube spacers with longer bolts.
The steering arm had to be heated and bent slightly inwards to compensate for movement. The setup works perfectly.
We used a Chevy 307 smog exhaust manifold on the left side of the engine, which has an indentation right where the steering box is located. We did this to facilitate for the tight squeeze between the exhaust manifold & the steering box. Another alternative would be to use an early 265 front-exit exhaust manifold or a GM exhaust manifold, part 346247 LH (Thanks to Gordon Wilhelm for supplying the part number).
The engine sits right in the middle and clearance between the right exhaust and the frame is minimal. With custom headers, the engine could be moved slightly to the passenger side if desired. Since the V-8 is shorter than the six, you've got plenty of fore-aft leeway in the engine compartment.
We're not giving you any measurements because their are several variables involved in this swap. However, I found that a 1960 Olds Cutlass driveshaft was just the right length. I mated it to a 1962 Chevy six-cylinder, three-speed, four-door sedan rear end with a Motor Master's combination U-joint. Once the engine and rear are mounted, you can probably find a driveshaft to fit at the junkyard.
I mounted a 1962 Chevy four-door sedan rear with a pair of spring perch pads cut from 2" channel stock. The axle must be located approximately 2" back from stock centering pin arrow. Drill hole in axle pad accordingly. I cut the coil spring bracketry from the stock rear end, fabricated the spring perch pads, removed two short leafs from each rear spring & bolted the rear axle in with 1957 Chevy U-bolts. You will have to convert to a 12 volt electrical system since all pre 1955 GM vehicles where 6 volts.
To operate my Advanced Racing Transmission's Bulldog Turbo 350 automatic, I chose a Hurst Auto Stick I lever-type floor shifter. It's about as rugged and uncomplicated as you can get. Unfortunately, I had to raise the shifter bracket about 4", tilt it forward about 30 degrees & lengthen the shifting rod to compensate.
The late model 283 is fitted with Isky"s Mile-A-Mor cam and Holley's Street Dominator manifold with a Model 4360, 450 CFM four barrel carburetor. This setup got us 2 mpg more & improved performance over the old six cylinder. Your stock radiator will work fine as long as it's in good shape, we had a custom 5 row radiator made for ours since our stock radiator had previous been swapped out for a radiator out of a car. If you use a flex-fan & not an electric fan for cooling, you will need a spacer since the V-8 is shorter than the six. We mounted the automatic transmission cooler behind the grille, in front of the radiator.
Final hookup included fabricating some throttle linkage, mounting the alternator to clear the fenderwell, hooking up the transmission linkage & attaching all wires, hoses, etc. I wanted to maintain the funny looking stock gas pedal, so I made my throttle linkage out of bits & pieces I had laying around. A 1955 Chevy throttle linkage or many cable-type throttle linkages can be altered to easily work as well.