I had a 2.73 10 bolt camaro in my 39 chevy for many years.It was great,and with a 6-71 blown small block I had plenty of low end power. I went to a 3.50 9" bronco a few years ago,and it feels like I am driving around in second gear.I don't put the miles on the coupe like I used to,so I will put up with the 3.50 gears for now.
If the 283 was still in good shape and there were no real worries about it breaking on the trip I'd run it and plan on making it a bit more efficient. Even if I used the stock two barrel on and adapter I'd run an Edelbrock Performer (used and cheap) and get a good electronic distributor. Going to an Hei on my 71 350 gave a gain of close to 2mpg right off the bat. That is doing 23 miles each way to work and back and a bit of running around at lunch time about 50 miles a day. That doesn't sound like much but on my truck it was a 20% gain. Driving habits are a big contributor. In July 1969 Danny Gonzales and I got out of the Army at Fort Hood at the same time and left there for LA in my 69 Olds Cutlass S 310 hp 350, Muncie 4 speed and 3.42 Posi coupe. When I drove we got 16 when Danny drove we got slightly over 18. He didn't run it through the gears like I did and he probably drove 10 mph slower on the average than I did. I did get one 90 mph speeding ticket near Roswell when I went down an on ramp and caught and passed two cars that were speeding that the cop who got me was clocking at the time. Still the state of tune, having the car set up so it runs in the engine's rpm sweet spot, having the front end aligned, tires aired up, brakes adjusted all just right so that there isn't any extra drag on the chassis all factor in.
The Hot Rod in my avatar would just sit back and relax at 60 /70 mph. I don't know what rpm, I had no tachometer. 327/300 hp. 3.73 gears, 350 trans, 450 Holly carb. cast steel intake manifold, Economizer cam, stock headers, turbo mufflers and 3" tail pipes after the mufflers.
Drivin form So Oklahoma to LARS the last 2 years in the car in my avatar. 355cu in, 350 turbo, 2:79's 31 1/2 " tall tire. Usually run 75 - 90 on the interstate. Both years got right @ 21 MPG for the round trip to included runnin around LA. It's all in the tune !!!!!!!!!!!!!!! If ya can't afford the fuel, don't go !!!!!! BTW, It'll still smoke em @ any stop light.
I think you will be pleasantly surprised how drivable that combo actually is when you get it together. I had a 350/350 combo in my 23 with a 3.00 gear ratio and 30 inch tire. It ran right along in town and on the interstate I got no less than 25 mpg and one time even got 30 mpg. It was a single Edelbrock 600 at the time and I cruised at 65-70 just off of idle. My one Son has a T bucket with a 306 Ford, C4 and 2.79 gears with a 29.5 inch tire. He is running 2 x4's and when he leaves a light I have to push the 331 stroker in my 27 to keep up. He is running a 3,000 stall convertor, which is what I recommend for you too. It will launch the car better and also work great at city and highway speeds. Too tight of a convertor will not allow the motor to get into it's operating band, but a looser one will. Don
""I think you will be pleasantly surprised how drivable that combo actually is when you get it together. I had a 350/350 combo in my 23 with a 3.00 gear ratio and 30 inch tire. It ran right along in town and on the interstate I got no less than 25 mpg and one time even got 30 mpg. It was a single Edelbrock 600 at the time and I cruised at 65-70 just off of idle."" At 70 mph the above is 2352 rpm..29.5 tire slightly more, don't think a 3000 stall verter would be locked up enough?
Because it's true. If gas mileage is such a big deal, maybe he does need a Prius. I just don't get trying to save gas in a hotrod. Selfish? Maybe. But I'm honestly having too much fun to worry about it. What's trying to get 20? 25? 30mph? Get everything tuned right and gas won't be an issue.
One of my friends has done exactly the same thing. RPM's were too low with 2.79 and he had an annoying harmonic. He put in a 3.25 and is much happier. I run a 3.08 10 bolt and have been happy with that (tires make a big difference too, I only run 235 70 15's on the back).
283 vs 350 is about 25% more cubes . You'll need to feed the 350 25% more every revolution 2.90 vs 2.79 is about a 4% difference meaning you're going 4% further for each revolution, & depending on your setup that may or may not equate to 4% reduction in rpms . 4% less rpm but @ 25% more each rpm. I'll predict your milage will be lower with the new setup vs old. More power but less efficient. You'll need to know the torque @ rpm for each engine to really get particular. I'd also say that you'll get better mpg & better performance out of your 283 with a small 4 bbl than you aregetting now. Keep your foot out of it though . Building & choosing with milage as "a" factor is one thing, rebuild, change, swap, redesign, regear with mileage as "thee" factor is completely another. Many many miles needed to break even on the latter. Ohh yea, WTF
Its a HotRod for christ sake. the very definition of which is a vehicle that is created for the enjoyment of the open road and if fuel economy happens so be it but this is not the primary goal. The GOAL is to look cool regardless of the refinments incorperated into the car. You put fuel economy first, buy a Prius, move to Boulder, eat granola and grow dreadlocks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Amen. People have asked me about gas mileage and I look at them like they are crazy. It's like Junior Seau's family sueing the NFL because his head got banged up playing football. Well, guess what, it's part of the game. Same with gas mileage. If it works out for you fine, but by nature and definition, these things were not designed to save gas.
I'll answer your question....I am not blind to a sincere question. I had a 51 ford car with 305 with dished pistons, z28 heads, turbo 350 trans, and a 2.79 rear end, I got 24.4 mpg running 70+ on the interstate on one trip and 24.6 the other time...I also had a 55 ford F100 with 305, flat tops, z28 heads, turbo 350, and a 3.00 gear....it got about 18 around town. Never checked the highway mileage. I do know that 350's are not known for their gas mileage with carbs. By the way, both cars above had a custom build quadrajet by me and my ol mechanic....the 2.79 gear should help you though milage wise. The 283 I am building for my fleetline has flat tops, Z28 601 heads, quadrajet, 700R trans and 3.42 rear gear...I am thinking close to 30 on the highway. Also, must add....the 51 and the 49 fleetline engines have 327-300hp cams....great for mileage and torque. PS...I am not fond giving oil companies all my money when they pay no fed income tax, etc, so I build them to save fuel costs.
Get the most out of every cubic inch and the most out of every drop of fuel with a combo of parts that work well togetger make you fastest in that class, also hot rod definition and a by product of being efficient. All depends how you look at it I guess. Mpg is more important the more miles you drive
That's a pretty ignorant statement, Anyone building a car should build it and tune it for whatever they intend to use it for.
Prius= garbage.please don't suggest one to anybody.the 2.79 gear and a 27 inch tire without overdrive is what a whole lot of 70-80s cars had.if you used a taller tire it will slow the motor down but as has been mentioned before if you lug the engine it will suffer more.i have a later model 80s Chevy truck some one added a700r4 and 30 in tires to.it got worse mileage because it never really gets in the engine sweet spot.ill be running 3:42 gears with no over drive on 29 in tire on this.your engine combo,weight and trans all come into play
Fine and dandy Mr mamby pamby but he stated it is a hotrod which has an intended use of being and looking cool, Period F@#%$*& DOT.
Is your 290 HP Chevy a new crate motor from GM Mexico ? if so I would remove the cam and get a look at the cam bearings. I have been getting a lot of these in as cores, defective returns, most with under 10,000 miles. Two big issues are the cam bearings installed wrong & second the intake valve seats cut off center, these are coming in with burnt intake valves, normally never seen. The cam bearing issue caused the oil pressure to drop very low after after the motor has a few miles on it. The last 4 all had both issues.
Oohhhh theres a lot of nastiness going on here, no call for that...we all have our own ideas about what our cars are for, I personally built my 36 pickup to see long distances. For power I run a bored 327, figues to 331, flat top pistons, 300 hp cam, camel hump heads, edelbrock intake and 625 carb, turbo 350, and get this, a 76 nova ten bolt with 2:20 gears, with a 235 15 inch tire. The truck weighs 2770 with me in it, the ten bolt was only produced with those gears one year I'm told by my rear end friend, I get a solid 25 miles to the gallon, when passing cars, it'll shift from second back to high at 80 miles per hour. Standing start is a good race for a five litre mustang, I don't often win, but my old girl does go good, its best is pulling out to pass at speed making killer rpm all the way to 80 miles per hour. I love my big gears, never had the guts to hold it open, don't know if it'll kill me or not, too old now to care how fast she'll go.
leave the gear...throw a vacuum gauge in and learn to drive with it... you'll be surprised what that can do. you'll like the 290 motor, used one in a 35 ford crew cab build ...ran great and had plenty of usable power..lol might look into a small 2000ish convertor...worked good in my turd
I'm re-gearing my Model A, before I put it back together. The past best average mileage was 28.5. I should see 30. Launches like hell, and will do 130. You naysayers either can't, or won't tune.
I agree 100% with you...I am building the fleetline to run nicely but the primary reason for the 283 is gas mileage and a nice souind....DUH!!!! Even my corvette gets good mileage for what it is....I can cruise the B/R parkway all day long on a 1/2 tank of gas....not bad for about 400HP. Everytime I see a prius driver...I give them the thumbs up...!!! They are the ones that keep gas prices down so you can afford to buy gas for your gas hog ...most of us don't own the Bank of America like some of you and don't care how much we spend for a gallon of gas...!!......Like the bumper sticker says...."Critical thinking....the other national deficit".... I have made it a personal challenge to bust 30MPG.....with a custom super car.
My dad ran the 350/260 hp/th350 combo on his car with 2.70 something gears and a 30.7" tall rear tire. With an Edelbrock 600 carb, 20 MPG was pretty common. THe car is a '34 Ford if it matters
Well, we are friends, but not like you know, bum buddies, I guess when you're impressing yourself typing away with one finger, you don't tend to see what others do......
There is nothing cool about passing un-burned fuel out of the exhaust. Wasting fuel for no reason makes no sense at-all, when that fuel could easily be used to make power. How does that Corvette make 400hp, AND get that mileage? Efficiency.
Yep, as stated- 279 gears plus overdrive will put you into lug-a-chug territory and your 350 will not be happy turning so low of rpms. I've gotten very respectable mileage from a 283 and 308 gears, no exact experience with a 350 and 279s though. A well tuned engine is being efficient and will make power and not be wasting fuel so get the tune spot on and it'll help possibly more than you thought. Oh, and Barack says to check your tire pressure.. Edit:I'm painfully slow at typing but gimp nailed it
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