xb 60 Glen Which power are you talking about? HP or Torque? IMO I will take 600+ of torque any day over HP. Torque moves the car and HP is needed at upper rpms to power the car in high speed.
You can't compare the original Shelbys with todays replic cobras. The frames are stronger, better suspensions, better engineering of parts. no wire wheels, Better exhaust systems. The list goes on. In the 60's they where the top of the list for great cars. Light power to weight ratio low, SIMPLE. How many people bought a cobra, drove it once and sold it. The number has not changed today with maybe 5-7% of all owners can drive a cobra to it's limits in control. I can't. I have fun with mine.
You have guys with cobras running 800+ HP. Some are animals, some are controlled without any problems. IN the old days you really had to drive a cobra and not get lazy at the wheel. Today we have the best of both worlds, Silly power, power steering, ABS brakes, FI systems, Traction control, even AC in the special few. I also believe that there are a couple twin turbo cars and blower cars floating in the mix. All streetable.
As far as big block against small block, it depends on the application of use. I do know that SB cars can chase BB cars all day on short tracks and some times win because of less power and better control.
The question of how much power, I am looking for enough to go 200 mph at Maxon. I still want to drive the car back to the trailer and not over heat.
The only issue with the power rating here on this forum is WHERE these numbers are coming from?? I bet 90% are coming from the crankshaft and not the rearwheels. FIgure a 20% of power for the drivetrain. You say 600 hp minus 20% and you have only 480hp give or take a few. My numbers are at the crankshaft of 520 hp and 618ft torque. Depending on tires, I can lay rubber in 3 gears. I don't because of tire cost and damage to the car and drivetrain.
RodneyM I will take the 511 twin blower car anytime. It's all in the setup. Put a waste valves on each the intake pipes, a balance pipe between the 2 pressure tubes. A electronic control waste gate system to control boost and a water injection system and you have one hell off a car for all sports. You didn't say if the car was FI? I would like a 47/53 front to rearend ratio of weight. Last notes, is the blower drive clog, surp or "V" belts?? Are the blowers gear drive internally or ball bearing? Once you get past 6-7 pounds of boost from a ballbearing blower they slip like crazy. Gear drive doesn't. And if you have the money their are now electronic motor driven blowers. Dial up the boost as needed. The rest is on the drivers skills.
Rick L