[azbirds]

For those of you running with the 200-4R. What gears are you using in the diff? I've got it behind a 455HO in a 72 T/A.

[moneypit]

I run a 700R4 behind a 455 in my 37 with a 3:73 gear. works out good for me.

[Steve C.]

Ditto.

3.73 / with 27.79" dia Nitto tires in conjunction with a non lock up Continental converter. At a steady state 70 mph cruise speed about 2300 rpm.
This presumbing the elec tach is correct. I know my speedo is accurate.

.

[azbirds]

Ok. I've got 3.42's. It doesn't even got into 4th until 65mph. The HO still pulls hard with that gear. I wish my tach was working so I could tell you the Ron's. Speedo say 90 when GPS says 70.

[azbirds]

I just noticed moneypit has the 700R4, is that also what you have Steve? I've heard the gearing in the trans is considerably different?

[goat1964-2004]

I’ve got 3.23’s in my stock 70 Judge. No issues.

[JLMounce]

Here's a datasheet with factory ratios for the different GM auto transmissions.

1st 2nd 3rd 4th Reverse
GM
Powerglide 1.76 1.00 1.76
TH350 2.52 1.52 1.00 1.93
TH400 2.48 1.48 1.00 2.00
200r4 2.74 1.57 1.00 0.67 2.07
700r4 3.06 1.62 1.00 0.70 2.29
4L60E 3.06 1.62 1.00 0.70 2.29
4L80E 2.48 1.48 1.00 0.75 2.08

The gear ratios of the 200r4 would seem to be better suited to the torque production of pontiac engines and would also allow for steeper rear gear ratio with the higher (numerically lower) final drive gear.

Another great option is a 700r4 with a 6 pinion planetary which changes the ratios to 2.86 1.56 1 .70. You get rid of the really low first gear ans shorten the ratio between 1st and second.

[skedadl]

Hughes built 200R4 behind my 461 with 3:30 gears. Works great.

[71 Goatman]

I have 3:42’s behind mine, always did like the 3:23 gears until I shredded the 8.2. The 12 blot got the 3.42’s. Good comprise between acceleration and highway cruising.

[Steve C.]

I have a 200-4R, again with a non lock up converter. That 2300 rpm I stated includes the slippage which is acceptable. I have no transmission cooling issues. A GPS indicates my speedo is correct. But when I converted to Fuel Injection the read out from the ECU indicated my aftermarket tach was off maybe 100-150 rpm at my set idle rpm (not unusual). But we never looked what the tach indicated out on the open road, that said I have been told a analog gauge will tend to be more accurate in the middle of their sweep. I'm ok with 2300 rpm indicated at a steady state 70 mph.


.

[azbirds]

Thanks for all the feedback! I'll keep it just the way it is, besides hooking up the electric for lock up. Before the swap my car would have used 3/4 of the tank by Wednesday. I have 3/4 of the tank left!!

[Navy Horn 16]

I also have 3.42's. I love it, though I would be a little quicker at the track with a higher numerical gear. I also have the non-lockup convertor so I can be cruising at about 2200rmp and 75mph, stomp it and take off like a rocket without even downshifting.

[azbirds]

We built mine with Art Carr parts. Billet drum, 300M input shaft and anchor pin. Shift kit and a better pump with red line frictions and more of them so it should be able to take a beating. I can't wait to get it out on a long trip at 75 mph to see what it will do.

[pont3]

I run mine behind a mild 455 with 2.93 gears. Roasts the tires for half a mile and 1900 rpm at 70mph. No lock-up but use a Hayden trans cooler.

[455'73inElCamino]

I am 3.73 gears with Art Carr 2004r, but am using a 2000 stall converter (stock stall) without a lockup., nitto tires 27.76".

Like others have said, 2300-2400 rpm at 70 MPH. I have had no troubles cruising in traffic at speed of 80+ mph without car or transmission getting too hot. In fact I find that my transmission cooler works too well and that the transmission does not really get up to full operating temperature. Or my temp gauge is not accurate.

[Steve C.]

From the internet....

In a perfect world you want to keep auto trans fluid temperatures between 175 and 200 degrees F, although I wouldn’t panic with a real-world 150- to 225- degree range. You don’t want to lean on the trans below 150 degrees, any more than you’d lead-foot a cold engine. On the high-end side, you could even slide by at 275 degrees for a short time during a long hillclimb but at the cost of considerably shorter fluid life. By 300 degrees you’re not only killing fluid longevity, but internal trans parts are melting down as well.

A lot of other opinions out there.

[Bobalong]

3:23
My hood tach says about 1800 at 60 mph with converter locked up.

Drove it on the interstate yesterday, 75 mph was just about 2200.
Just an awesome cruiser, no screaming engine / gas guzzling / temp issues. But can still
smoke the tires in 1 st gear.
Everything is a compromise. I like being able to keep up with traffic w lower rpm's.

Installing the rostra cruise control next week.

[pastry_chef]

So many enjoying the 2004R, nice to see.

[455'73inElCamino]

Because I was a worried about excess heat buildup due to not having a lockup torque converter on my 2004r, I bought a simple LED temperature indicator that changes color as temperature increments upward.

What is great is that it is inexpensive, easy to install/mount and doesn't take up a lot of space like a gauge. I mounted it to my tach which is always in view while driving. Also, the sensor end plugs into the transmission on the drivers side and the wire/LED just gets routed up into the car. No tubing of transmission fluid required.

I figured this indicator might be of interest to you guys but I can't seem to find vendor who I bought it from.

If someone has used this and knows the vendor, please post if anyone is interested.

[RA462]

My 65 GTO has a 433, 200-4R, and 3.73 gears out back. I'm at 2000 RPM at 60 with the converter locked up. Recently I installed a 3000-3400 stall converter and removed one of the governor springs. It's not as street friendly as it once was so I think I have to install the spring again and see what that does. I have thought about changing to 3.42 gears.