Alright. Well i guess it sounds like Rear end Gears are'nt gonna get me where i want. And yeah the 351 swap is'nt gonna make gas $ priority. I dont do much freeway driving either. So how come lower gears wont be 351 freindly?

 

I've got an idea! If the point is to save gas buy a KIA and save the mustang for the go fast stuff.

 

I think you should just sell the car to me..

 

I have to agree with soaring on that one. The 3.25s are a great compromise. However, I really have to question your 3000RPM at 60. unless you have very very small dia rear tires, something here is WRONG! Read the responses from people here, you should be doing 2500/2600 at 60 max! are you sure your tac is reading right? get this sorted before you decide on gears, because from what you have said so far, its not adding up.

 

Heres all the specs again. And its a new high quality tach hooked up to MSD ignition.
302
3.25 gears
14" Rims
Toploader tranny

If that doesnt sound right at all there is one more possibility. We believe the previous owner used the car on the strip quite abit (he blew the old 351, removed heater core connections, removed AC and removed Powersteering) Possibilty he regeared the transmission? It may be slight but theres a chance, we dont know.

 

nah 4th would still be 1:1 if the gears where changed. In a manual trans the top gear is simply locking the input shaft to the output shaft.

I figure it this way. My cars cost me money. I have like 30+ so I dont worry about it. I think more in terms of how far can I drive on one tank because I do alot of highway long distance driving. Just went from Lake Superior to South Carolina and back last week. Thats a long trip. So getting 300 miles froma tank of gas means fewer stops to me so I get home faster.

The point is, does it really matter how long it takes to pay for itself in fuel mileage if you go to a 5 speed? You can get a TKO for $1700 that will almost bolt right in there. Its an upgrade to your car and it will make driving mor pleasant and fun. Saving gas is a bonus IMO. I figure less engine wear on cruise is worth more to me than a gallon of gas, because I spend around $3500 or more to build my engines. So at $3 a gallon how many gallons do I need to save to pay for the engine I just ventilated?

If you are serious about your old car, you will save money to make changes. You will make a budget and live by it so your kids can do college and you can have your toy. Its getting to were driving them daily will be too expensive, not just in fuel but everything else. Parts will become more scarce, and even oil will make a difference. Right now if you have a flat tappet cam you shouldnt be running off the shelf oil, they have removed the zinc because it ruined catalytic converters. The zinc lubricated the high wear spots like the lobes and lifters. If you are running a low zinc oil, your cams days are numbered if it isnt already gone. heavy truck oils have the zinc, so I am runnin Rotella in my old engines. FYI.

One of the better ideas was to get a daily driver that isnt your Mustang. That will allow you to work on the Stang and fix things on nights where you have to work tomorrow. Time is valuable to you even more so than gasoline is even if you dont realize it. Add the 5 speed, stick with 3.25 or 3.55 gears, then add the 351. Right now you culd go with the 2.80 or lower gears, but you will work that little 302 pretty hard especially with a top loader.

One nice thing about your rear end, you can have multiple gearsets for it, and swap them in over an hour or so. One for performance, one for highway cruises. If you have enough power, you can still rundecent with a highway gear. I have two cars that have 2.73 gears, both run mid 13's and one of them gets 30mpg, the other gets 19-22 with an overdrive trans. Build torque and you can use your highway gears, save gas, and still embarass the ricers.

A cheap fix most people have gone past is tire diameter. One inch increase in diameter will gain you abour 10mph for a certain RPM. So if you have 25" tall tires, going up to a 27" tire will get you about 20mph more cruise for the same RPM. Go measure your tires and see if something taller will fit in there. Taller tires also have advantages in drag racing. They have a larger contact patch and more traction. Simply swapping some 15" rims and a 235 65 15 or a 235 70 15 would make a difference. They should fit under a 70.

 

Very well said. The 5 speed does sound like a good option for me, in the future. I may have to wait 6 months or a year until i get into that kind of decision. I just graduated, in between jobs and trying to get ready to ditch the celica and get me 8 grand of play money. My priority right now is to get this thing into a daily driver asap. Tranny swap, new motor now before paint etc, i dont have time, yet. And i will have a second mode of transportation for driving as well (extra family car can only use temp though)

So yeah, i may go either 3.00's or stay 3.25 (soaring shut up i know ur grinning) because with an eventual motor and/or tranny swap, with nothing but city driving, and with the short time before major changes come, i should keep the performance and sacrifice a couple pennies on gas. Thanks again all.