Anyone get decent mileage out of a stock 401 in a 65 A-body with a four speed and taller than stock gears? Decent mileage to me would be 20 mpg. To accomplish this I would have to remove the stock t-10 and replace it with a wide ratio four speed and say 3:08 gears, or higher. Any input would be appreciated. I have been toying with the idea of putting a 65 Special on the road with a 225 v6, but I am running into lots of modifications to get decent mileage and the GS is pretty close to road worthy as is. Any input appreciated.
guy on here put a 700r4 behind a nailhead and got over 20 out of a wildcat mixed driving od is the key but you will need a adapter from say eelco or transmissionadapters.com etc... eelco is the cheapest for a tranny adapter if your wanting to bang gears a modern day 5 or 6 speed would be the way to go eelco makes a adapter for this also
I get the same milage as Doc on my 64 Riv unless I put my foot in it. I got 7 mpg last year fighting a headwind in Nebraska. Of course I was going 90 most of the way.
These calculations are representative of a car (my '64 Riv) running a 3.08 rear end, a TH200R4 transmission (.67 overdrive ration) and 225.70/15 tires (27.4" diameter). Surely there's some gas mileage in there somewhere, assuming the nailhead has enough torque to move the car down the highway at 1600 RPM's. I would think that with a HEI ignition, and runnig the front throttles on a Rochester Q-jet, that 20+ mph would be well within reason.:beers2: Input Parameters Are the Following: Differential Gear = 3.08 to 1 Transmission Gear = 0.67 to 1 Tire Diameter (Inches) = 27.40 Engine RPM = 1600 Computation Results: Computed Vehicle MPH is 63 Let me know if you think my thinking has gone south. Ed
My 65 GS will get almost 20 if you drive it at 60 mph. It has 3:23 gear and 15 inch tire. The only thing is a good 2.5 inch exhaust and good tune up with a cure kit with medium springs. This is a two speed auto car. It makes bette mileage than my stock 68 350 GS. Thanks Bill.
I'm beginning to see a theme here, seems the nailhead in an a-body with tall gears gets pretty good mileage. The nailhead has the torque to handle low rpms at cruising speeds if geared accordingly. My experience with nailheads has been with low gears in the rearend and the mileage was around 13-15 per gallon. I am going to check the rearend gearing in the two 65's in my yard that I could swap out to my driver and try to find a wide ratio t-10 so I have a bolt in solution and I can still get the car to move away from a stop sign without ruining the clutch. Thanks for all the responses, Kurt
Kurt, Put this in your pipe and smoke it. The T-10 you're referring to has a low gear of 2.64; a 200R4 has a low gear of 2.74. If you run a half-way tall gear of 3.23 behind your T-10, you have a first gear multiple of 8.53 - That will save burnig up your clutch. You'd have a final drive ratio of 3.23; you might be able to get some mileage out of that. BUT if you ran a 200R4 with a 3.42 rear, you'd have a first gear multiple of 9.37 - much quicker off the line. BONUS, the 200R4 with a .67 overdrive and lock-up torque converter would give you a final drive ratio of 2.29 - think how much better mileage you'd get with those numbers. The 200R4 will be quicker, faster, and get you better mileage. I'm using the 200R4 over the 700R4 for various reasons. 1) it's smaller externally and you don't need to hack up the floor pan and redesign a trans tunnel 2) It has a .67 rather than a .74 overdrive. 3) it will shift into o/d at WOT. 4) The trans mount is within 1/16" of a TH400 trans mount - use the existing transcrossmember and open the hole a smidge. 5) it has dual Chevy - BOP bellhousing patterns cast in. Ed
1. with a 700r4 you wont need to hack it up either just shorten the drive shaft and modify the rear cross member. 2. its actually .70 on 700r4 and .67 on a 2004r so your not talking a whole lot of difference... but much deeper 1st gear on the 700 so you have harder launch. 3. actually a 700 can be set up to do the same its not good on either tranny. 4. all that is required to mount the 700 is move the cross member back an inch or so. if you can use a drill you can do it. 5. 200 does have both but a nail doesnt use either and you need a adapter kit still. the 2004r is a great tranny but the bad side is there expensive to buy cores build strong etc... a 700r4 is on ever corner and can bought for nothing and built real cheap. my advice if you find a 2004r cheap jump all over it cause they are great. if not a 700r4 may be a good mod for you. if your wanting a manual however look at a modern 5 from a new vehicle. i think mustangs came with a 5 speed tremec.
My old 65 GS hardtop with the T-10 4-speed and 3.36 rear gear with a bone stock engine got 18 mpg on a long road trip.
i think in a a body car with a od tranny and good tunning you could see 25mpg throw a few little extra things like lose the clutch fan headers maybeye fi etc.. and you could see 27 mpg thats crazy
with the stock rochester 2 jet and a fresh rebuild i got 20 mpg at 75 with stock gears in my 63 lesabre with a dyna
now howscome my late model vehicles with the fancy pants computers and efi wont get but about 17 out on the road at best with a 6cyl.?????????
On a recent little trip to chicago I averaged 15 mpg with my foot in it quite a bit. I know I could do better.............if someone else was driving the car! :Brow: Thats from a stock 401, dual quads, msd distributor, 3:08 gears, and a st400 trans.
My "Adjustable, Variable Ratio Roller Tip Rocker Arms" will help in the MPG department as well as a "Performance Improvement". On my '64 Riv. with the 3.90 gears, a big Holley dbl. pumper & keepin' the R's down to around 3K I could pull almost 16MPG. Now with the 3.07's back in with everything else remaining the same can pull close to 20MPG if I keep my foot out of it & keep the speeds around the 65-70 area.
more weight and emissions but a crown vic with about the same weight gets about the same even though it has a smaller motor
Not yet, I've done the chassis and brakes so far. Next will be the engine. When I put the engine in, I'll put the 200R4 in it then. Date: postponed until I get through therapy on my back and have a chance to rehabilitate it. Ed
