9manastacio

iTrader: (4)

I have an l98 350, with a t-5 5 speed. Currently, I have 4.10 gears, but was wondering if a 3.42 or 3.73 would be better. I know the 4.10 are better for torque, but I want acceleration and speed balanced. Any recomendations?

9manastacio

iTrader: (4)

a

84 z28

3.42

9manastacio

iTrader: (4)

what i was thinking, with 4.10s i think that driveshaft just has to spin too much for the wheels to turn, good for torque, but not the best for speed, somewhat...lol

84 z28

4.10's arent anywhere near good especially since you look to have a stock 350 tpi. Those motors run out of steam in the blink of an eye.

AlkyIROC

4.10 may be good for stoplight to stoplight driving but even with an overdrive, it's too deep for the 26" tires on the highway. 28" tall tires and 4.10 with an OD can handle highway speeds easier.

2.77 gears would suck for performance on the street but the engine would be idling at highway speeds.

"Best gears" depends on what you want to use the car for. For day to day mixed driving, mid 3.xx is a good ratio. For mainly highway driving, mid to high 2.xx. For drag racing, whatever gear allows the engine to max out it's rpm as you cross the finish line in high gear (not OD).

UnderCover89TBI

iTrader: (25)

I have heard TPI saying they ran quicker 1/4 miles with 3.23's over 3.42's and 3.73's. I run 3.42's in my camaro I think depending on tire size its the happy medium for take off power and top end speed. as well as fuel mileage and etc. I know I get to drive in the 1/4 mile a couple hundred feet before the traps. when the engine is still pulling. But you really wanna be topping out for optimum performance right before you go through the traps.

blackbmagic

Great post

In my opinion as you start to upgrade your motor or swap you will want a higher gear ratio to get better E/Ts.To answer your question, With your setup I think 3.73's would be good or even 3.42's. You could get a taller and wider tire to give you some more traction and less spin off the line and in some cases more speed down the line. Alky is right these motors stock do run out of steam fairly quickly.

I would stick with the 4.10s if your planning on doing motor work do it and get a taller/wider tire.
When I went from a 235/65/r16 to a 275/45r18 they handled the power and 3.73 rear much more efficiently.

theNMBR27

I run 3.42's and they're still tolerable for the highway. 4.10's are overkill on a stock motor in my opinion.

robg91z

iTrader: (1)

i have the same question here...3.73's or 4.10's???..i have a L98 TPI 350 with bbk underdrive pulleys, afpr, headers, and a built 700r4 everything else is stock and original..the 3.73's are looking good once i came into this thread. i was thinking of going with 4.10's but u all are pretty much showing how 4.10's arent really good for a pretty much stock TPI..so 3.73's would be my best option?

blackbmagic

Depends on how you drive your car and what your plans are. Are you going to keep it stock and is it a DD. If it is I wouldn't do any more than 3.73. If you plan on racing at the strip and using larger tires with higher HP I would go 4.10s.

Pro Built Automatics

What is the 5th gear ratio in this transmission?

blackbmagic

700r4 has "4" gears. Not five. 4th gear ratio is 0.7

Pro Built Automatics

Posted by 9manastacio. Quote, I have an l98 350, with a t-5 5 speed. I want to know, what is the 5th gear ratio in this transmission?

blackbmagic

0.63(TBI) 0.74(TPI) Are the ratios in the Borg Warner t5. Sorry I was still thinking about robg91z question.

robg91z

iTrader: (1)

well the mods i have posted it wat i have for now..thinking of getting some heads and a cam swap and thinking of going HSR 383 later on..but that wont be til later and car is not really daily driven i just take it to school when i feel like it or just go cruise and mess around the streets(local track closed so the streets is where the action has been happening) so wat do u say? and i do plan and running et streets or drags with some drag lites and bigger/wider tires just depends how big of a tire i can put on my 3rd gen..so wat do u think??

red rock

iTrader: (2)

I have a stock 350 with all the mods you can do without going into the motor, chip, throttle body, runners, ported plenum, bypass, etc. I have a stock 3.27 borg warner 9 bolt posi. I built a 9bolt 3.70 gear that makes great low end torque and power though the power band in the 1/4 mi, and only lost 250rpm difference at 70 mph. The 3.70 will bite with better traction and less wheel spin on take off, I lift the front end more and spin the tires less and don't lose that much less on highway driving. Over all i like the 3.70 gear better. The 3.70 gear is similar to the 3.73 10 bolt in rpm range, so i think you will be better suited with the 3.73 with a stock motor than the 4.10. However if you start hitting the 380-425 hp the 4.10 will then start preforming better in the 1/4 mi. This is only my perspective and my opinion on my experience? It may be mechanically easier to change tire size than gear ratio, but what ever you do you will have to change the speedometer gear ratio accordingly to have an accurate reading.

blackbmagic

I don't recommend street racing but you will do what you will do. If you are on the street higher gear ratios will perform the best with the right tire setup. With 4.10s Your 0-60 times will increase and stop light to stoplight you will be much quicker without any modifications at all. So I would go with the 4.10. Also when you start upgrading you motor you will have a better platform for the strip.

Your speedo will be inaccurate, you will get poor gas mileage and your car will be winding at highway speeds.
But as you said its not a DD so these things really do not matter.

AlkyIROC

When I had 3.27 gears many, many years ago, I had enough HP to push the car to 12.0 @ 117 mph. The gearing wasn't correct for the combination but I still made them work.

irocket87

i have a mostly stock 305 tpi automatic iroc with the exceptions of headers exuast. i have 2:73s i think and im running 15.5s in the 1/4 now. its mostly a daily driver. i also am thinking about putting in 3.73s, how much in the quarter would i pick up if i went with a 3.73?

9manastacio

iTrader: (4)

I changed the speedo gear, i have the correct one for 4.10s, modified a th350 gear to work with my vss, as accurate as it can be. can anyon e tell me what there t-5/v8 combo revs are @ 60 with 3.42 and/or 3.73?

Drew

iTrader: (58)

Since TPI makes the bulk of it's power at lower RPM it doesn't make a lot of sense to put steeper gears in the back since that will raise the RPM for a given speed. The longer you keep the engine in it's happy place, the faster the car will go (to an extent). That's why 3.23 and 3.42 gears work so well in these cars. GM had 3.73 and 3.70 gears, that they used with the higher winding carbed cars, but for TPI it's borderline too much gear.

blackbmagic

Very little if nothing in the quarter mile. The 305 tpi's dont pack enough up top to use the higher ratio to its full potential. You might benefit from a 3.27. But with a 3.73 or a 4.10 you will really loose out up top were it counts for your motor. If you do get a 3.73 or 4.10 expect to swap out to a bigger motor or heavy modification on the 305 to reach full potential with these gears.

Pro Built Automatics

2 tenths on the average with this gear change only. Good torque converter even with 2.73's will get you 5-7 tenths in the quarter mile.

Zepher

iTrader: (1)

When I was stock with an auto, 3.23 to 3.73 gears dropped my ET half a second and I picked up 3mph. 15.7 @ 86mph to 15.2 @ 89mph.

when I switched to a T5 and 4.10 gears, my ET stayed at 15.2 but my mph increased to 93mph.
4.10's were fun but too much for highway driving and since my car is my daily and I use the highways often I was burning up gas like it was leaking out.

blackbmagic

Sounds like when you changed your trans this gave you speed on your top end. Switching from a 3.73-4.10 wont give you more speed unlesss... You have a taller tire.

And wow had no idea that going from a 3.23 to a 3.73 would have that much of an impact on E/T with stock platform. Ive always heard that a stock motor will not perform better with a higher gear ratio in the quarter only 0-60 and 60'. I also have never driven different gears on the same platform. Always have swapped gearing when there was more power available.

VictorMonsivais

red rock

iTrader: (2)

What transmission do you have? An Auto or a stick? What gears do you have now? Either way, 4.10 gears are way to high for a stock 305.

VictorMonsivais

red rock

iTrader: (2)

First gear in a 700r4 is 3.06, you combine that with a 4.10 rear gear and you will be shifting immediately to second and third. With a stock 305, you may get a jump up to 50 feet, but your engine will run out of power (to high of rpm). You will throw the whole power band off for the engine you have. 4.10's are for huge power engines. You would benefit more from from a little higher stall converter then you would for gears. According to TGO, you have very low power. https://www.thirdgen.org/1991-chevy-camaro/

VictorMonsivais

dmccain

iTrader: (2)

I have 3.73s and really they are too steep for my 305 TBI auto car. I plan to change to 3.23s or 3.42s next time I get into the rear end again.S10 t.c.. Really was a big help to mine also, id say it gave it 2200-2400 stall.
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midias

I have had 3.42 and 3.73 with both the .62 and .73 5th gear T5. My preference is .63 5th and 3.73 but I also drive 20 minutes on the expressway every day going to work. .73 with 3.73 gave great 5th gear acceleration but I like cruising at 500rpm less.

red rock

iTrader: (2)

A stock LO3 with 170hp and a 2.73 gear is where VictorMonsivais is at. There is going to be a lot of money poured into making any gains in performance. I would start with building more HP first, depending on whether to keep the 305 or go bigger. Or just stay stock and enjoy the car.

dmccain

iTrader: (2)

Adding some gear and TC is the best seat of pants you can give an Lo3. Mine is way more fun. Doesn't feel as slow as it really is. I also have a well built tranny that shifts snappy. huge upgrade from 2.73ss and sloppy tranny.

Majik723

Best gear ratio to run for 1/4 mile track and occasional city driving with a 383 stroker and beefed up 700r4 in my 92 rs. Wanting to switch rear end to disc brakes also. Suggestions

427seven

Need to post more info, the 383 can be a low rpm or a high rpm runner, where is the power made in the motor?

John in RI

iTrader: (167)

MY rule of thumb when ALL other things are equal:

700R4 = 3.42
T5 = 3.73
T56 = 4.11

Driving a 700R4 with anything over 3.42(5) is too quick a gear for any highway driving -----> IMO.

84 z28

I have a 700r4 and 4.11 gears and is just fine on the highway, tire size helps also

John in RI

iTrader: (167)

Sure; you can get on the highway,...... but at 2800RPM @ 75MPH your not doing any "highway driving". What's a taller tire get you,... drop a couple hundred RPM maybe ?? Heck; on a typical highway drive I don't even drop my T56 4.11 into 6th until AT LEAST 80mph.

84 z28

You're not driving that fast where you live or where I live on the highway, speed limit is 65 in which like I said is a fine crusing speed/rpm for a 700R4 and 4.11 gears

John in RI

iTrader: (167)

84 z28

If you're ever on the highway & see this:




,............. Just get out of the way.

84 z28

LMFAO