Thread: Highway RPM question....

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Drive 100mph.... Problem solved

-Chris

I would also worry about stall speed and trans temp......the mid 90s camaro had a 350 with a six speed manual and would cruze on the highway at about 1200 rpms a 60 mph....but that is a different situation all together from his.

My opinion for what it's worth.

Drive much faster ..

Let me guess that he doesn't had a external tranny cooler either.Those 700's do not like heat.

I would guess this car is 3500lbs to 3800lbs too.That comes into play as well.

The 700r's I think get a bad wrap.Yrs ago Art Carr build a bunch of them for the local police force.All that abuse and mileages and when the cars where retired,not a single failure.

In my 70 pick up I have a fuel injected 302 with a AOD trany and 3.25 rear end gear.
It does that jumping up and down in gears at about 50 to 55 MPH.
It's a dog all the way around in the performance class, so I keep it in drive till about 60 MPH then I pop it up to over drive. Now keep in mind this truck weighs over 5 thousand the way it sit's. Now this thing can run top end pretty good as long as there is no hill or a strong head wind. If there is a hill or a wind it will get to about 75 MPH and won't pick up any more speed. So yes this is a big dog, but it was this way when I bought it.
The motor does not have enough torque with those gears and trany to pull strong.
The only good thing is the 30 plus miles to the gallon it gets.
Kurt

I know your right Louey.
My motor and trany came out of a 79 licoln cont.
The rear was already in the truck, it's a bad combo
is all I was trying to show. I would put a C - 6 in it
but the guy did such a good job on the install I have left it alone.
Kurt

I am running 2.41 gears in my 54----
it has a turbo 350 trans--so final ratio is 1 to 1----

at 70 Im running around 1800-----Im running a comp cam with a power band of around 1800 to 5400----while the low rpm is good for gas mileage, Im running the bottom of the band and it is just a little doggie-----

However, Im 65 yrs old, Im a little doggie too!!!!! For a cruiser it does ok, as a ground pounder------it wont!!

Originally Posted by katie

I am running 2.41 gears in my 54----
it has a turbo 350 trans--so final ratio is 1 to 1----

at 70 Im running around 1800-----Im running a comp cam with a power band of around 1800 to 5400----while the low rpm is good for gas mileage, Im running the bottom of the band and it is just a little doggie-----

However, Im 65 yrs old, Im a little dog too!!!!! For a cruiser it does ok, as a ground pounder------it wont!!

Well I'm 66 years old and I love my 4:56 gears and a Muncie 4 speed ,
Forget about mileage have fun

Originally Posted by vara4

In my 70 pick up I have a fuel injected 302 with a AOD trany and 3.25 rear end gear.
It does that jumping up and down in gears at about 50 to 55 MPH.
It's a dog all the way around in the performance class, so I keep it in drive till about 60 MPH then I pop it up to over drive. Now keep in mind this truck weighs over 5 thousand the way it sit's. Now this thing can run top end pretty good as long as there is no hill or a strong head wind. If there is a hill or a wind it will get to about 75 MPH and won't pick up any more speed. So yes this is a big dog, but it was this way when I bought it.
The motor does not have enough torque with those gears and trany to pull strong.
The only good thing is the 30 plus miles to the gallon it gets.
Kurt

How in the world are you getting 30mpg out of a 302/AOD in a 5 thousand pound Ford pickup????

With those gears he`d be better off with a th350... or change the gears.

I don't know how the guy did it he is a buddy of mine and is 76 years young.
All he has done his whole life is electronic's and fuel injection system's.
He hates carb's and switches carbs over to fuel injection all the time.
He's got 3 older Ford he's working on right now, a 65 a 69 and a 70.
He does the same thing with motor homes.
And his son is some kind of deisel god, he heard of a tug boat sinking with two brand new diesel motors on it, he went out and salvaged it for about 20,000 went thru both motor's then turned around and sold them for 40,000 a piece. Not a bad deal. These guys are good at what they do. I had my old bronco in the shop about 5 time's to the tune of about $2500 and they couldn't fix it. I took it to this guy one time and he fixed it. That's how we met and we have been friends ever since.
Kurt

Originally Posted by vara4

I don't know how the guy did it he is a buddy of mine and is 76 years young.
All he has done his whole life is electronic's and fuel injection system's.
He hates carb's and switches carbs over to fuel injection all the time.
He's got 3 older Ford he's working on right now, a 65 a 69 and a 70.
He does the same thing with motor homes.
And his son is some kind of deisel god, he heard of a tug boat sinking with two brand new diesel motors on it, he went out and salvaged it for about 20,000 went thru both motor's then turned around and sold them for 40,000 a piece. Not a bad deal. These guys are good at what they do. I had my old bronco in the shop about 5 time's to the tune of about $2500 and they couldn't fix it. I took it to this guy one time and he fixed it. That's how we met and we have been friends ever since.
Kurt

Interesting! And of course, he couldn't be farther away from me! LOL! I would love to try to get better mpg's from my 66 F100 352, automatic. It currently gets about 10mpg.

Randy

Kurt has hit on the secret.......fuel injection and computers. Even modern full size cars are getting great gas mileage compared to the older ones. On the highway my Northstar gets almost 30 mpg.........around town is another matter altogether.

Don

You should take the camshaft into consideration, too. There is an operating range listed with most cams. In my case it is 1800-6000 rpm. I have a 700 R4 with a 3.89:1 rear gear and 30 inch rear tire. I cruise at 2200 rpm in overdrive at 70 mph. Around town, I drive in D rather than O. It will do okay at 1500 rpm in slow traffic, but regular driving, it likes 1800 rpm and above.