Canadian trucks? Or would those have been metric by then?
I wonder what are the DSOs of the 100MPH trucks? There has got to be some reason why they got those 100 MPH units.
My '77 has the 85 MPH speedo.

Regarding the OP, the fastest I've seen on that speedometer is 55 or maybe 60. I've got rust holes in my roof, and my tires are showing some cracking... But my speedo indicates less than actual MPH because I believe that my 235 75 15s are really supposed to be 215 75 15s... So they're 1.2 inches taller, which I feel also pushes the limits of the 3.00:1 gears. The interim fix will likely the next size or tooth-count speedo driven gear.
Long term solution might just be a 3.25 or 3.50 chunk...

 

I drove my 1974 F100 with a 4v 390 from Arapahoe Colorado to Sharon Springs Kansas in 12 minutes. It's near 25 miles
Distance between Sharon Springs, KS and Arapahoe, CO
I was in Highschool and very stupid but that truck was 30??? years newer than they are now.

 

75 or 80 is quickest I've gone in mine. 400 with 4.10 gears and 4 speed. Engine sure doesn't like those higher rpms either.

 

got my 74 highboy up to about 110-115 and thats with a (I think) 390 4spd 4.10s and 33's

 

Indicated on the GPS on private property was 96.3 mph. 390 c-6 auto 3.50 gears and stock 15" tires.

 

I have a 1973 F-250 with a 390 4 speed and I had it up at 90 MPH! 373 gears in rear end.

 

That is funny!
I have gotten my78 F-100's 85mph speedo all the way around to the 10mph mark, which I estimated was around 130mph!!!

But it did have a 1970 429ci in it.

 

78 302 and fast enough to get a ticket in any school zone in the USA.

 

120 on I90 in Montana(;

 

Had a 1974 F-100 as my first vehicle. Had a 390/C6 in it when I got it too. Rebuilt the 390 in '89, putting 428SCJ valves and a good port and polish job on it. Make a long, fun, story short. It did 13.28 at Sacramento Raceway at well over 100 through the traps. If you want to go fast, first make sure your IFS is in very good shape! Check all tie rods, kingpins, and bushings. This is usually where all the shaking comes from. My original speedo only went to 100, but I have buried the needle several times with no problems(somewhere in the 120-130 range). I originaly ran stock tires and 3.50 gears, but went to 31x11.50 and 4.11's for bracket racing it. The C6 was never a problem. I had power to burn and plenty of low end to boot.

 

I believe most trucks were exempt from that rule. Just sayin'

 

The 360 and 390 are the same engines. Only difference is the shorter stroke, but same diameter crank bearings on both, which made them so easy to convert. 352, 360, 390, 406, 410, 427, 428 were all FE series engines and the parts were surprisingly easy to swap, with good balancing. Cranks were 3.5 to 3.98 in stroke. All nodular iron except the 427SOHC crate engines which had steel cranks at 3.78", same stroke used in 390, 406. The 410 was the first 3.98 crank and eventually morphed into the 428 CJ/SCJ. Putting a 428 crank into a 427 block yields a 447 at the standard 4.23 bore.

 

1979 F100 stock 302 T18 3.25 235/75R15 85 MPH speedometer back up past 5 MPH downhill no traffic

 

I don't get how some of you highboy owners are claiming 100 mph, lol. My truck is all stock drive train wise, '77 F-250, np 435, 4:10's and 35's. When I get her up to 70-75 it feels like it's about to explode. I don't have a tach, so don't know if I'm at 3k rpm's or 10k.

 

I have a 1979 2WD with a 460 and 4:10 back, no problem getting to 80 even. Runs smooth as butter, no shaking. I don't think I've gone faster than that yet but I wouldn't foresee any issues