Just wondering what top end speeds I should be getting for 1988 211 liberator with 464 king cobra outdrive. Outdrive and prop (21 pitch) are in excellent condition, topping out at 48mph and I was sure it ran faster last year.

What are your RPM's at wide open throttle? Do you know the gear ratio of the drive? I would think that set up would run about 10 mph faster.

I would guess at somewhere around 56-57.

I am assuming you have a 460 Ford, not a 464 or 454.

The 460 in a 211 will run mid to high 50's, I have had several friends who have had that combo in the past. A 454 in a 211 will run low 60's.

21" pitch should be about right, with around a 14" diameter.

That engine should be running at least 4600rpm at wide open. I used to run 57mph in Liberator with a 14.5 x19 prop I think, been a few years.

Your engine may be getting tired, a compression test is a good idea