I am putting a 200r4 tranny in my 72 Cutlass with a 2:73 gear ratio I am thinking about 3:43 or 3:73. My question which would be the best gear and would it be an advantage to install limited slip while I have rear end apart. I am thinking about using gears from Quick Performance anyone ever used them before.

 

3:73 is the way to go and with the better ratios of the OD you will have the best of both worlds. JMO. Never used that company I always use Richmond Gears.

Johnny

 

If I went with 3:73 if would probably be better to go with limited slip. I have heard that the lower you go the more time you spend spinning the rear tires, is that true?

 

with the OD trans go with 3.73 or the aftermarket 3.90. Do not go with 3.42 or numerically lower.

 

^^^This. With the 0.68:1 OD, your 3.73 gears are effectively 2.54:1. At the same time, the 2.74:1 first gear in your 200-4R will result in a final drive ratio in first equivalent to using 4.06:1 gears with a TH350.

 

Thanks for the input think I will go with the 3:73 but what about limited slip

 

You'd be crazy not to install it now.

 

Thanks Joe I will install while I have it out have you ever used rear gears from Quick Performance?

 

Sorry, no.

 

https://www.summitracing.com/parts/d...a556/overview/


http://www.jegs.com/i/Detroit-TrueTr...2A556/10002/-1


best bang for the buck and I believe it has a 50.00 Rebate too

 

I used 3.42 gears with a 25" tall tire, with my 2004R and the converter locked, it ran at 1850 rpm at 60 mph. What size tires are you running and what other mods? I am considering 3.90 gears, want a bit more at the track and no 3.73 for the Type O rear.

 

I am running 24 and 1/2 inch tires you can see the build on my engine below, car don't start to run good until i get about 3500 rpm's with 2:73 gear. Then runs strong on the top end just wanted something quicker out of the hole.

 

What tire is that short?

 

P225/60R14 Goodrich TA's if you look at actual spec they are 24.7 at 35 PSI I run 32 PSI in the rear.

 

So I think we can all agree it's time to put a real tire under that car.

 

Wow. That tire would be small on a Civic. The original tires were about 26-26.5" in diameter. Even the BFG 245/60-14s are too small in my opinion. Yeah, the smaller diameter tire makes up for the Bonneville gearing a little, but there's WAAAAAY too much daylight in the wheel well in my opinion. I'd go with either 225/70-14s if you want to stay 14" or 255/60-15s if you get real wheels.

 

The BFG tires seem be short on height, my wore out 245/60R14's measured a hair under 25", supposed to be 25.6". Others with fairly new tires have been worse. You may have a 24" tall tire. With your cam, either 3.73 or 3.90 gears would be better, especially if you go with a bigger tire.

 

Sorry guys I made a mistake they are 245's not 225's but still only measure just a bit over 24 and 1/2 inches and only have 9000 miles on them

 

Sorry Joe I made a mistake they are 245's. Does not show it on my profile picture so I sent this picture it has been dropped 2" in front. Do you still think 15" tire will fit?

 

The 255/60-15s will definitely fit in the rear. Probably not in the front with the drop. You could probably get away with 235/60-15s in the front.

 

That might be an option because I am also thinking about installing headers and am worried about ground clearance with the 245-14's

 

Check your math sir. 245 60 14s are 25.6" tall.

https://tiresize.com/height-calculator/

 

https//photos

here are a couple of pictures so if I am wrong the ruler is wrong

 

Not trying to argue what size chart says they are I am just saying what size mine are. I looked at chart myself and mine are not as tall as chart says. The thing that gets me is they have very little wear on them only 9000 miles. I am now wondering how they could be that far off.

 

Because they are not measured with weight on them.

 

And I had 255/60/15's on 7" SSII's all the way around on a 70 with BADLY worn springs and they never hit in the front or rear.

 

Thanks man didn't know you had to take them off car to measure height. Glad I posted photos so this could be cleared up. I was thinking for a while I got cheated on my tires. I am always ready to learn that is why I joined the forum.

 

Choosing gears is unbelievable hard- especially if you line out how you want to build you car, like i, who want to keep TH350, even i admit the that theres nothing like OD-trans.

Out of interest ive studied such a simple thing that speedlimits at US at 60's, 70's. Like 55mph law and how it was received and accomplished. It was actually pretty interesting story. Well, it wasnt only out of interest, studied it to understand gear-ratios offered by factory back then.

Problem with 1:1 trans comes at both ends, you really can just choose "worst of both worlds" in my opinion. Thats what makes OD transmissions so great.
Part of the problem is also nowadays speedlimit, and speed of normal traffic-flow.
Up there you need atleast 75mph just to keep up with traffic, and at summer times 80-85mph is the norm. Towns here are far and long away, so using old roads with lower speedlimits really arent an option, until you have plenty of time. Highways are used for travelling.
But i like to drive my car like i would drive my DD, with the traffic, not going longer way with lower speedlimit.
Example: My way to work, using highway, at summer time 40min. Using old road, which is also longer, 1hr 30mins. No thanks.
Last summer i drove hmm.. Cant remember anymore, but about 5000 miles i think with my Cutlass.
Coming summer our summer-trip alone is 4000 miles with Cutlass, + all the other driving, so i really need to think about every aspect on subject.

Lets see. If you pick up the gears so that you can bear the revs at upper limits, you really dont get hop from stand-still. If you choose gears so that you have great off-the-line performance, forget about riding at motorways.
Friend has 3.90's at his Valiant with souped up 360+727.
GREAT fun around town, and close roads. Fries the tires with a flip of throttle. But freeway? Forget about it. That takes the fun out of those gears from me. Not to be able to drive where-ever you want with any sense to time used for travelling.

Ive personally settled long ago to 3.42 or 3.23 for aforementioned reasons. With 1:1 final drive transmissions. Not low enough to have great grunt from stoplight, not really high enough to keep revs down at freeway, or help at freeway mileage. So, worst of both worlds. Part of the charm

Th350 gear ratios are 2.52, 1.51 and 1.00, 1st to 3rd.
Compared to, for example, TH200R4- 2.74, 1.57, 1.00, 0.67 1st to OD.
Starts lower ( greater torque multiplication) and ends higher. Theres no contest which is "better" in terms of street usage. And this frees up you to choose rear-gear ratios way more deliberately. TH350 with 3.42 gears are suddenly an "~2.3's" at OD on TH200R4.

You could say theres a whole world behind such a simple hearing thing as rear-end ratio, when you take all things into equation.

 

Makes sense, I measured my bald ones off the car, they were around 25", new ones would be what a 1/4" more? I will measure my new 245/60R14's I am buying in the spring before they go on.