Last question for my 71 350 4bbl. Opinions needed as to what is the best overall gear for street and highway. I have 2.56 gears now and was thinking of going to 3.08's for some more kick off the line. Looking for the best of both worlds! Opinions welcome!
What size rear tire do you intend to run?? Ther is really no correct answer to this question.. On my GS I run 3.08's and a 28" tire 275/60.. It's a go anywhere do anything combo..
I run a 3.42 and a 2004R trans in my 350 69 Sport Wagon. and it gives you the best of both worlds,decent acceleration and 20 MPG I have a 3.31 and a 200-4R in my GS and it pulls 13.2 1/4s and 16-17 MPG I have a 2.56 gear and a TH400 in my 37 coupe and it is good for 16 MPG tops and it is a high 13 car
A 3.08 with a 26"-27" tire is pretty good all around IMO. You don`t seem like a die hard "Go Fast Guy". Going up 52 notches on the ratio ladder..you should notice!!! Later,Tony.
I have 3.90's in mine and it suck alot of gas....Fun as hell though! I'd suggest either a 3.08,3.23 geaar for cruising and if you decide you want a little more umph..3.42's I had a 70 GS 350 with a somewhat stock 72 GS350 motor in it with a M20 4 speed with 3.42's and got 16-18 mpg and ran mid 15's..
I have 3.08's and I'm probably not going to change them. I totally think that is the best "overall" ratio unless you have a direct wire transfer from your bank account to the gas station and have endless amounts of money growing on all the trees in your backyard. From a slow roll the 3.08's are a blast. plus at 60mph you're not screaming. You will find that most folks on the board may tell you 3.42 is the ultimate gear ratio. Personally that's a little steep to me if you're gonna drive it a lot, unless you have 4 gears. My presumption is that if you plan on driving your car fairly often you may not like them. As it is, with 3.08 you will go through fuel like a drunk goes through gin. Plus with 3.08 you'll have more left on the top end. This is of course just my humble opinion. :beer
Lowest (highest numericaly) I would go WITHOUT an overdrive is 3.42 Even without overdrive 3.42's are a bit "buzzy" on the highway at 70 mph, and gas mileage sucks. 3.08's to 3.23's are a better choice if your close to a stock engine.
There is no single best answer without an overdrive transmission. It is a matter of your acceleration goals versus how fast you want to twist the engine and fuel you are willing to consume, when cruising. Shari's GS 455 originally had a 2.56 final drive ratio (installed by a previous owner) behind a slightly warmed up 455 which overall had decent acceleration and great cruising characteristics. When we changed to 3.08 was amazed how much the fuel mileage went down, like Ken mentioned above, but was a quite a bit more responsive. Finally installed a TH 200 R4 like the Old Guy - Joe mentioned followed by a switch to a 3.42 final drive, which makes for an overall of 2.29 effective ratio, with the .67 overdrive forth gear. An added benefit is the lower first gear in the TH 200 R4 compared to the TH400 for even a slightly better 60 ft. time, if you maintain traction. With the overdrive you have the best of both worlds, with the acceleration you bought the Buick for and the ability to cruise at 75 mph at about 2400 rpm, with 26 inch tall tires, and the torque converter locked up. Did Joe mention he drove his 350 69 Sport Wagon with 3.42 gears and overdrive transmission to the BCA Nationals in Colorado last summer without missing a beat, even with the side trip to Arizona.
