The break-even $$ time on a Gear Vendor overdrive becomes shorter every day, with the way the gas prices are climbing. I've got the same problem on my 1983 Motorhome. 33 foot RV+454+TH400 = 7 mpg.
If you want to keep the motor, look into a factory 454 TBI setup. It'll be cheaper and work as well as any aftermarket setup. If your willing to swap the motor, the 350 TPI motor from F-bodys are actually pretty good torque motors. More torque than a TBI anyway, and they don't cost much more than a TBI motor these days. The swap really isnt any harder either since you're just plugging things in. You will need a high pressure fuel pump though. unless you need it, swap out the Th400 for a Th350. There's less paracitic losses with the 350. A Lockup would be even better, plus the trans will last longer. Change your engine and diff over to synthetics. They move easier and cause less HP loss. Although I'm sure you already have them, a good set of headers and free flowing mufflers will help too.
put a diesel in it....I had a 81 sub with the ****po older diesel chevy used (before the duramax) and got 25 mpg at any speed! 3/4 ton too with a 700 ******. My current ride is a 3/4 T ford excursion with the older diesel (before the new POS) and with big exhaust,hypertech tuner and cold air kit I get 18 on the highway and 15 around town.....and you could always brew your own biodiesel for about a buck a gallon! Oh yea...I can smoke a tire and pull anything and any hill easily....much better than the old sub!
I have a factory TBI 454. I've never seen it do better than 10 mpg. I have 4.10 gears and a TH400. I'd look for ways to slow the motor down before swapping to TBI. I know some people are getting 20 mpg from modern big Diesel pickups, but I don't think anyone with a 454 is going very far on a gallon of gasoline. I've done the math, even at $4.00/gallon I don't drive mine enough to justify spending much to improve it.
My neighbor bought a 1982 Mercedes 300D and put in a waste veggie oil conversion ($1000). For the last 10,000 miles (he's a traveling salesman), he's put a total of $20.00 of diesel in it (WVO won't start up cold, has to purge with diesel upon shutdown). Do THAT math - 10,000 miles; $20.00 in fuel cost. The restaurants have to pay someone to come get the oil, so they'll give you all you want, for free. My own 300D is too rusty, so I just bought a 300CD coupé for conversion. Cosmo
I have to point out diesels will run on veg oil with no convertion at all 98% oil 2% non organic thinner.(just leave for a week)...I have a mate who runs his golf turbo diesel on veg oil and occasional diesel, He has chipped it to 230 bhp and gets 45mpg while out running the golf r32!!!!!! I have also to point out gas is around $9 a gallon here and I don't give a ****...I run my A (zz4 and 15 mpg) as much as I can afford which includes going to work in it... anyway the sooner we use all the oil the sooner all the stuff the oil companies have bought and hidden to ensure we continue to buy oil based products will suddenly emerge.......
I grew up in used cars, my dad drove fixed and raced cars never less than 10-20 years old... i don't know, maybe i like something i can get under the hood and still recognize ****. Sounds simple, buy a different car... duh. That's not what this thread started out asking, and thanks to all of you who have taken the time to give us very sound advice. We're parking the Suburban (purchased for $600) for use in towing and hauling tasks when they arise, gonna keep it full of fuel and crank it up once in awhile to keep it fresh. My old Falcon (purchased for $1000) which is getting a Mustang 200ci inliner swap soon will be her 15-20mpg work vehicle. The pickup I'm getting built (purchased for $700) has a mild 350/350 combo that will be a decent work truck for me. Saving the 'burb in hopes of someday finding a 50's or 60's 'burb body looking for a frame/drivetrain to ride on... then it'll be worth takin' down mainstreet once in awhile! (between gas stations!) I was trying to get more mpg from a mill that just wasnt made for squeezing gas - thanks for all the help folks!!!
Paul, I always thought veggie oil was fine as is. The only thing I've heard is that some cars need a heated fuel line, or a valve between the tanks so you start on deisel and then switch over. What is all this "refininf" everyone mentions that costs a buck a gallon???
My 2 cents FIND HER A JOB CLOSER TO HOME ..... LESS GAS USED LESS TIME DRIVING/SLEEPING IN CAR(SAFER TOO) SAVE MONEY SAVE ON REPAIRS TO THE "ALMOST FREE DINOSAUR" SPEND MONEY ON FUN THINGS MORE TIME SHE CAN BE WITH YOU - ELIMINATING NEED FOR 2ND GIRLFRIEND WHO IS ALWAYS HOME AND HAS SOME CASH! PAPERDOG
Quisenart, I went thru the same **** when I was in college. I had a '77 chevy pickup with a built 454. Got tired of the gashog so I saved up my money and bought a Holley projection TBI. It was a pain to setup, but once I got it tuned right it was great, way more low end torque and I could actually get up close to 14mpg on the highway. Now, I've converted to flatheads, in addition to being the coolest engines ever built, they get decent mileage too. Nevermind the fact that I spent $4,000 to rebuild an engine that only has 150hp, how smart was that? Gary
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