Optimum cruise rpm.

[turbohunter]

14/15 seems to be about average for mileage .
I got 14 on my last trip to Montana with my 360.
Was figuring with the 441 and a GV inline I could stretch that out.
Gonna keep my 3.50s for now as my deal sees a lot of highway miles.
I've got plenty of low with an NP 205 on the back of my 435.

Nice truck Wes

[Drew Pojedinec]

Drew, with the GV unit and the 4:30's , what was the effective ratio when the GV's unit was engaged?

2800 rpms with 4.30rear gears and the GV engaged results in 70mph.
2800 rpms with the original 3.25 gears and no overdrive resulted in 70mph

So essentially I've got 4.30 to help move the heavy car and 3.25 to cruise with.

here is the rear end build on my car if you are interested: http://www.fordmuscleforums.com/makin-progress/553305-2013-progress-my-63-5-galaxie.html

[machoneman]

Thanks! Very informative.

Drew, with the GV unit and the 4:30's , what was the effective ratio when the GV's unit was engaged?

2800 rpms with 4.30rear gears and the GV engaged results in 70mph.
2800 rpms with the original 3.25 gears and no overdrive resulted in 70mph

So essentially I've got 4.30 to help move the heavy car and 3.25 to cruise with.

here is the rear end build on my car if you are interested: http://www.fordmuscleforums.com/makin-progress/553305-2013-progress-my-63-5-galaxie.html

[chris401]

If you said 6.0 Id call bs. No one would keep repairing and no company would keep you on for tearing up there trucks. I did run my tired 500,000+ IDI 7.3 down the devide 80mph in 3rd around 3800 rpm's. The throttle body gas engine are better for engine braking.

Company?  I owned the company.  and the truck was an 89 f250 with  7.3IDI and a c6 transmission.
Cruising at 65mph just resulted in that kinda rpm.  At that 270,000 miles I put a zf5 in it.  Man, that was awesome.
Best combo I've found so far?  My Galaxie has 4.30:1 rear gears and a GearVendor....  Perfect for my usage.  Tho if I were to do a lot more open highway cruising I think 3.89 woulda been nicer.

They will take a beating. Ran mine in od against the limiter at 3100 a lot.

[fe66comet]

Most of my FE service trucks ran about 2500 depending on tire size. They seemed happy and sure lasted a lot of miles. Most had a C6 with a 3:70 and lets face it a old service truck with a couple tons of pipe threading tools and HVAC parts does not get gas mileage. I sure missed the torque when they went to the 351 and even the injected version was only 7 mpg at best compared to the FE that got nearly 15 with a 650 Holley. I hate TBI horrible stuff Ford, GM or Dodge, sputtering, wheezing , gas guzzling mess.

[Grbmaverickmo]

My cars 390 seems happy at 2300 to 2400 range on a steady cruise with the 3.25 rear and stock cam gets 14mpg to 15 depends on what gas I use.

[bn69stang]

Jon i agree with you , 3.70 s are a good all around gear for a street driven fe , when you throw the calculator at it - 3.89 s with 28 inch tire is bout the same rpm as 3.70 s with a 26 inch tall tire .. comparison  275/60-15  -  275/40-17 , and the 17 inch tires are cheaper than the 15 inch tire , My buddy has a 69 with 17 inch wheels , bigger brakes and a coil over

[bn69stang]

oops , it handles and stops awsome .. Bud

[fe66comet]

I put that gear in my Ranger project, with a 5 speed I figured it would be a nice gear.

[bn69stang]

Yeah i don t want a quarter mile assault vehicle , want an all around car drive it and enjoy it . Bud

[bn69stang]

Just want an honest 525 hp big block under the hood , a nice driver to enjoy any where .. Bud

[fe66comet]

Nothing wrong with that. Just don't. Let your brother or buddy borrow it LOL.

[bartlett]

I have a c6 3:70's and she rolls 3,200 at 65 ... she is singing right along ...

[bn69stang]

Thanks for the reply s guy s ,