The Stovebolt Site Forums The Parking Lot Big Bolts Reasonable cruising speed

Hello, I'm sure this has been asked a hundered times. I tried a search but didn't find what I was looking for. What can I safly and reliably cruise my 1960 C-60 at? Or better yet what rpm would be the target at cruise? Thanks for any reply on a subject i'm sure has been beaten into the ground.

58-62mph should be safe. . .the best 3,000rpm is Max on the GMC V-6 or big block V-8's inline 6's should hold 3250rpm and the small block v-8's can handle 3500rpm. . .

As a rule of thumb I use 3,000rpm as my max speed across the board. . .

Mike

What engine, do you have an overdrive or is 1:1 your top gear, what rear end ratio, and how tall are your tires. engine will tell us the RPM range and the rest I can plug in and give you approximate top speed.

I've had the firetruck up to 55 but I wouldn't push it. As for a C60, I'd guess you would be in a simular size motor and truck as mine.

Flat out on level ground..... my '49 runs happily at 50mph...of course that gets slower (or faster) depending on hills and/or other terrain..........
Michael


speed is relative..... just not one of mine....lol

my K-3000 run's 62.5mph@3,000rpm the 379M-V6 seem's happy at 3,000 rpm.

the B61T run's 72mph@2,000rpm I changed the mack triplex for my own version of the triplex. I combined a later model mack 5spd OD tran's with 3spd auxy now i got 2 OD's then i added a turbo to the 711END to create a 711END-T,stock 58mph@2250rpm now 72mph@2,000rpm. . .I gained 14mph and 2mpg. . .

mike. . .

Freq2002, I'm running a 261, my top gear is 1:1, I am running 20 inch tires. As far as my rear end is I do not know the ratio. It's a two speed vac operated out of a 59'. I had a chipped gear set when I got the truck and I just replaced the third member. Apparently I had a 59 diff in it. I suppose the result of a early truck manufacture during a model change. Thanks!

My '62 GMC 6500 with a 478 V-6 would go 62. But the truck was in real good mechanical shape and I would only run it that fast for short spurts.

50 to 55 seemed much more of a favorable cruising speed.

Bill

sound's about right. . . i had 1980's C-60 with a 350 that would run 65mph@3250rpm. . . with some over sized tire's. . .I put 11.00R20 T-831 Firestone tire's under a 8.25-20 Truck. . .

what will that 478 Hold for R's about 2500 ? 2750 top's ?

mike

Mike,

The truck didn't have a tach. It had a place for it, but it was blank. It had all the other gauges, air, oil, water, ammeter, but no tach.

But it was probably maxed out to what a 478 goes to at 62 MPH. I'd have to look it up to be sure.

Bill

If the 478 would cruze 3,00RPM I would swap out my 379M-V6 or a 478M-V6 in a heart beat. . .

Mike. . .