Rpm On The Highway

What would be a comfortable rpm on the highway for long periods of time? Im running a 258 with a t18 and 4.10 axle gears on 31s. I know the tire size and gear ratio isnt optimal for the highway but its what i’ve got. I am pulling around 2600-2700rpm at 60 mph.

 

What year? You're fine. The factory 4.27 ratio is fine even with the shorter factory tires. How fast do you want to go?

 

Its a 1973. I was wanting to do around 65-70.

 

Those numbers are a little high to be called comfortable.200-300 rpm drop would do wonders. Problem is how to get there. Gears or tires and loose off-road performance. Or live with it and get a second vehicle.

 

3.73's

 

70 is about 3100. Does that worry you? It's fine for the engine if in good condition. I would take measures to dampen the engine noise and drive it.

 

The engine is in good working order. I’ll try having it up at 70mph at see how I feel about it.

Eventually I will go up to 33s which would definitely help.

 

3.73" in axle, 36" tire runing around 2200 at 60 mph

 

373 with a 32 about 2500 at highway speed.

 

With the numbers you gave I think your on the right track . 33" with 4.10's might be the sweet spot for you.

 

Thats what i was thinking.

 

I ran my Tux up a bit higher than the "9" on the speedo several or more times in my younger day. 235/75-15 tires with 4.27 axles, and a Buick 215 that liked high rpm. I never had a tach, but I'm guessing I was approaching 5K. My friend's Ford F150 4x4 couldn't keep up.
I ran that combination a lot on the interstate at an indicated 70mph, and it was comfortable for an hour or two, no problem!
I really like the 4.27 gears for all-around use. I never had a good overdrive back then.

 

Had it up to 65 the engine was at around 2800 handled it really well it just was very loud! Have not had it on the freeway yet because its been very wet down in socal and I do not want to go the fastest i’ve gone in it on a wet freeway.