I drive my 52'GMC 454-30 at 55 MPH. that is the fastest it will go.

It has a governor under the 2 barrel carb and a raised metal stop plate under the throttle pedal.

It purrrrrrs at 55 and gets good gas mileage at that speed.

Also another thing some people forget is not only the brakes but the front axle wheel bearings are not designed for modern highway speeds. It is a good idea to upgrade wheel bearings to a higher grade bearing. They cost more, but are worth it if you plan on spending much time on the freeways and turnpikes.

And good tires as well

Dance like no one is watching,
Sing like no one is listening,
Love like you've never been hurt.

1948 GMC FC101 1/2t Pickup w/270 and SM420
1948 GMC FC253 1t Factory 80"x9' Flatbed Dually
1948 Chevy COE 2 Ton 8'x15' Flatbed
1950 GMC 354-24 2 Ton 8'X12' Flatbed w/Dump Hoist
1953 GMC 454-30 3 Ton 8'x14' Flatbed w/Dump Hoist
1953 GMC 454-30 3 Ton Cab and Chassis
1942 Clarkator 6 MILL-44 Heavy Aircraft Tug
1942 Ford (9N) Moto Tug with 1/2 yard Loader
1947 Oliver OC3 HG-42 Tract-Crawler Bull Dozier w/6' Blade