And now, the rest of the story.
Most of our long wb A-bodies are gonna come around 3400 pounds plus driver. Duster and Demons being lighter.
By my yardstick a 3600pound car then needs a
[email protected]/cube.
but lets say your 318 car comes in at 3200 pounds with you in it. At 1.0 hp per cube=318 hp. You got the power. But that power is at 5200 or more rpm. At 2500 to 3500 where you do most of your driving, you gave up low-rpm power to get that hi-rpm power. So the bottom has gone soft. So you slap a 3000TC on it and 3.91s and everybody is happy, right. Well maybe, if you don't mind 65=3400 rpm, and 9 mpgs. say your engine makes 280 ftlbs at 3000 stall, that is 160hp at WOT.Say your car requires 40 hp to cruise at 65mph; that is 25% of available power.
Say you had a 360/318hp which is .88hp per cube. But with the extra cubes comes more low-rpm torque. Furthermore, the much smaller cam required to make the smaller absolute power, also makes more low-rpm torque. So now, you don't need to run the 3000 anymore, nor the 3.91 gears. You still need the same 40 hp to cruise with, so say you choose a 2400TC and 3.23s. Now 65=2750 or so. Suppose this 360 makes the ame absolute power of 160hp @2750 rpm. And you are still using 25% of it to cruise with...... but the rpm has dropped from 3400 to 2750. That's down to 81%; good deal. And you still have the same 318 hp at the top, but now maybe it comes in 600 rpm sooner; that's an even better deal.
of course, with the 360, you could run a lil more gear and a tiny bit more stall, and have a whole lotta more fun, versus the 318 which as to streetability, is as good as maxed out.
Now, you might think that from 3180 pounds to 3600, is only 420 pounds, which is correct, but that 420 pounds at WOT represents 42 hp. And to take a 318 from 318 hp to 360hp
without killing the bottom-end, normally aspirated, is as good impossible, unless your pockets are very deep indeed.
