17mpg!!!

[Project1970]

That's why I installed the 700R4.

I pulled a nice 13MPG on the way uphill from Phoenix to Tucson...and 17 on the way back. Woohoo! Quite the improvement from the previous record of 9.8, which was up from about 7.

On a side note...wish me luck in court today, hopefully I'll still be legally able to drive this thing...

[1-PU70]

I got 13mpg with my 402 with 700R4 , 3:73 rear and 31" tires. That was towing a car with a car dolly.

[Huck]

21MPG, 5speed, 350, duals, HEI, 308, he, he!!

[ChevLoRay]

Uphill, from Phoenix to Tucson? I don't remember it being uphill, but that was 32 years ago. Now, if you went through Reddington Pass, I can see Uphill!

Anyway, I think you gotta be bragging. I don't know what I'm getting, but it's better with the Edelbrock Q-Jet, than it was with the Edelbrock 1405.

A 700R-4 is on my Christmas list. I doubt that I get it, tho. I'll just make do with my TH400 and my 3.73's. Been doing it that way for 3 years, so what's time to a hog?

[Project1970]

It's not a steep uphill, not at all; in fact, it looks flat, but you actually are climbing about 1500 feet (IIRC, Phoenix is at 1100 feet, Tucson is at 2600 feet). And enough to change 5mpg in mileage, too. I'm not bragging but I am quite satisified that I got such an improvement, not just in mileage but in drivability. I will never put a 3 speed auto into a street car again...

Huck - nice.

For the record, my setup:
Original shortblock 350 (will be toast within a year, my guess...lotsa blowby)
Vortec heads, Edelbrock Performer intake
Edelbrock #1901 Quadrajet
No-name aftermarket HEI
700R4 from Phoenix Hard Parts (kinda indifferent on the people but the tranny is nice)
3.73 rear end
275/60-15 tires (28" tall)

2550RPM at what the speedo says is 80mph...gotta do some math and make sure that's right.

That HEI was also one of the better things I did for mileage, it was what got me from 7-8 to nearly 10.

[palallin]

Previous Truck: '67 C-10 SWB Fleet, 327, Q-jet, Saginaw 4-peed, 3.07 rearend: 23 mpg highway.

Current Truck: '69 K-10 (same) 327, Carter AFB, SM-465, T-221, 3.73s: 13 mpg highway.

[Alexis]

have you guys seen/heard about the BMW 6 speed auto transmissions, man think about that in one of our trucks, hmmmm adding two more gears to the 700. that would be pretty cool

[busterwivell]

Man, I can't wait to get my 700 in! Wish I didn't have so many projects going at the same time!

[nate68]

i haven't had enough consistency to get my mileage yet. bad plug wires, bad plugs (i changed those), now its intake gaskets leaking (changing them tomorrow)
after i change the gaskets everything should be running right enough to see the improvement. town mileage still sucks, plus the motor is still new. i'll post when i find out.
i know i wont be getting 17mpg, but better than before. runs 1800rpm at 60 (i think). 3.50 gears and 28" tires

[Project1970]

Originally posted by alexmart1
have you guys seen/heard about the BMW 6 speed auto transmissions, man think about that in one of our trucks, hmmmm adding two more gears to the 700. that would be pretty cool

Yeah, I think it's a ZF unit.

ZF also makes the 6-speed / PTO stick in the GM HD trucks, and the 6-speed transaxle in the current Corvette.

Hmm.

Or, slap a GearVendors unit on there...8 speeds, and you get rid of the nasty 1-2 gear space (which is just plain steep if you ask me)...they're what, .74:1 overdrives? Which, when split between the 3.06/1.62/1.00/.74 gears of a 700, would get you 3.06/2.26/1.62/1.19/1.00/.74/.54...yes, that's only 7, because I realized that 3rd on the 700 with OD enabled on the GV is the same as 4th on the 700 without the GV enabled.

With that .54 overdrive...you could run 4.11s around town and get better cruising RPMs than a 700R4 alone with 3.73s...or imagine a 700, GV, and a 4.56 rear.

[nate68]

with that setup on a swb the driveline would be extremely short!

[Ackattack]

I must need to do something about my carb...edelbrock 600.

Does anyone on here have a T-56 in their truck? 50% overdrive in 6th gear!

[Project1970]

Originally posted by Ackattack
I must need to do something about my carb...edelbrock 600.

Does anyone on here have a T-56 in their truck? 50% overdrive in 6th gear!

I was very tempted...and if this had been the '73 Camaro RS/Z28/LT I almost got instead of this truck, it would definitely have been a T-56 instead of a 700R4...there's a T-56 in our '94 Z28 and that tranny just kicks serious @$$. Give it a change of synthetic ATF (screwy, huh ) every 80,000 or so and it'll last forever...it's just that IMO, the length of a floor shifter required would take the fun out of a 6-speed stick.

It's the same stick they put behind the V10 in the Viper originally, and I think they still do. IIRC, it's also used in the new SVT Cobra, and the older Cobra R. Tough as nails, with a great gear-ratio setup.

[TERRYP]

'66 Panel, 350, 3.08, 200R4, Q-Jet, rams, dual ex, Reno to Cheyenne, 75 mph, 13.6 mpg. Denver to reno via US 40, sticking float, 55-60 mph, 9.8 mpg