[Sizzler]

The following values are for illustration purposes only, though I’ve actually seen/heard them associated with the equipment:

C-6 25% loss between flexplate and rear wheels
C-4 15% loss
5.0L 350 horsepower at the flexplate

difference between C-6 and C-4 is 10%, or 35 HP for the 350 HP engine.

This is how you can lose 35 HP by using the C-6 instead of the C-4.

I’ve never actually dyno’ed an engine and then rear-wheel dyno’ed the exact same engine after installing a transmission, so I can’t verify the losses. This is a constant (shades of SB vs BB) point of discussion in benchracing rear-wheel dyno results…trying to back into what the engine is actually putting out HP-wise.

As for using C-4’s in drag racing. Yes, racers use them. They also rebuild them and/or examine them regularly. Drag racing is also a much different class of use than street driving. I’ve taken this position with oiling mods, and I also think it applies to transmissions. The C-4 can be built. Torque is the killer of transmissions. If you use a C-4 behind a high-torque, make sure it is built to withstand such treatment.

I’d still pick the C-4 for your situation. You’ll ‘gain’ effective HP at the rear wheels and reduce the weight of the vehicle. All good things.