273/4 -318 debate
Commando 273 engines were 4 barrel engines and had a number of special HP parts. The 318 was a 2 barrel work horse that had the best Warrantee record of any American V-8. Not being theoretical, I actually ran a 66 Formula S 4 speed Barracuda on the street. Raced from a stop more than a few stock 318 2 barrels. No chance, not even close. Nothing anywhere it's size was it's match, even with 100K on the speedometer. A lot of cars could get the jump on me, but once she hit 3,000 rpm she took off and I'd pass them like they were standing still. Having a 1,000+ higher rpm range is also a big factor. A friend of mine has a 67 4 speed Formula S Fastback and had his 273 dyno'd. With all the Commando good stuff and 2 barrel pistons, a small Isky E-4 cam, and a 600 Edelbrock carb the little 273 made 260+ hp at 5,500.
In general If you are building any wedge engine, you should be able to get 1 hp per cubic inch and torque as well. A good 273 will move a 65 Cuda very well and get 20+ mpg. 66 Cuda's were lighter than the 64 and 65. A High Performance 273 likes rpm and will easily run to 6,000 to 7,000 rpm with stock heads. I had a 64, 4 speed Cuda as a daily driver for decades. Loved that car. Here are some stock hp numbers from one of the Chrysler Racing manual. Notice that a 318 2 barrel does not make any where near 230 hp. Depending on what you have, all engines are similar in cost to build. What do you have available? What do you really want the car to do? Start there.
Commando 273 engines were 4 barrel engines and had a number of special HP parts. The 318 was a 2 barrel work horse that had the best Warrantee record of any American V-8. Not being theoretical, I actually ran a 66 Formula S 4 speed Barracuda on the street. Raced from a stop more than a few stock 318 2 barrels. No chance, not even close. Nothing anywhere it's size was it's match, even with 100K on the speedometer. A lot of cars could get the jump on me, but once she hit 3,000 rpm she took off and I'd pass them like they were standing still. Having a 1,000+ higher rpm range is also a big factor. A friend of mine has a 67 4 speed Formula S Fastback and had his 273 dyno'd. With all the Commando good stuff and 2 barrel pistons, a small Isky E-4 cam, and a 600 Edelbrock carb the little 273 made 260+ hp at 5,500.
In general If you are building any wedge engine, you should be able to get 1 hp per cubic inch and torque as well. A good 273 will move a 65 Cuda very well and get 20+ mpg. 66 Cuda's were lighter than the 64 and 65. A High Performance 273 likes rpm and will easily run to 6,000 to 7,000 rpm with stock heads. I had a 64, 4 speed Cuda as a daily driver for decades. Loved that car. Here are some stock hp numbers from one of the Chrysler Racing manual. Notice that a 318 2 barrel does not make any where near 230 hp. Depending on what you have, all engines are similar in cost to build. What do you have available? What do you really want the car to do? Start there.