Hot Rods 1951 Buick rearend question

I am looking at getting a 51 Buick Super hardtop that has a dynaflow trans in it. How will the car do at highway speeds? I have searched quite a bit online and cannot find much info. As far as the current owner knows it is all stock, running but not driving. Thanks

 

I have a 52 hardtop, all original running gear and it does great on the highway. Runs at 70 mph with no issues. Not sure what the RPMs are but it's not topped out. Still some room left under the pedal for passing

 

When I was a kid we had a 48 Roadmaster convertible and every year we traveled from Pa to Florida for vacation. It went right down the road, and my Dad was not a slow driver. That big straight 8 would just loaf along at highway speeds.

Don

 

Cool photo Don.

 

Thanks for the replies guys. That is a great photo Don, thanks for sharing!

 

The 51 Buick, because it is an auto, has really good highway cruising gears in the rearend. My 50 was a 3 on the tree and was tough to cruise on the highway.

 

The dynaflow works just fine at hi way speeds in my 51 super. Like 52_super said, at 65-70 she still has some pep for passing.

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I think there is still 2 different axle ratios for the dflow. should be stamped on the bottom housing. I cruise 65-70 mph well. can hit 80mph but I backed down immediately. I am not running a tach. next on the list.

 

Greetings I had a 1947 Buick Super with a three speed that would run best at 70 to 90 miles a hour and give me 22 mile to the gallon all day long!Uncle Bill

 

Uncle Bill............where can you run downhill all day long????

 

All of my 1951 and 1952 Buicks would run 70 MPH all day long but I never got 22 MPG even coasting down hill with the engine off. They did get a steady 14 to 15 MPG though. You should find the 51 has a 3:42 rear gear and the engine will be turning about 2800 RPM at 70 MPH with 760 X 15" tires.