I was just running the numbers for the OD swap in the Imperial.
I will be using Edelbrock heads on a stock-ish cam 440 and shoving around a 5300 lb Imperial. It wears 3.23 gears out back.

Without OD I'm looking at 2500 rpm for 65 mph and 2900 rpm for 75 mph.
With OD I'm looking at 1700 rpm for 65 mph and 2000 rpm for 75 mph.

1700 rpm seems pretty low for a 440 to lug around that much weight. Is that too low for an efficient cruise? Stepping up to 3.55 gears would increase rpm by 250 or so.


Please stay away from the "engine should run at peak torque rpm blah blah blah" uneducated BS. We all know that's not true in the real world. If it were true, our cars would get amazing mileage at 4000 rpm.

On the up side of things, with the 3.23 and 518 if I could hit 6000 rpm the car would be cruising at 228 mph.
Do you think John Force has a spare engine I could borrow?

We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind.
- Stu Harmon