TH7004R or TH2004R?
 

I want to change out my tranny for a locking 4sp. I had been leaning towards the 7004R until the other day when I read that the 200 is virtually a direct replacement.

I'm looking for comments and or experiences from those who may have already done one of the swaps and any information as to the major differences between the two.

I don't race, I don't really even drive hard and my motor problably puts out between 250 - 300 HP max. I do a good amount of long distance highway driving in addition to daily around town driving.

Thanks
Chris

Re: TH7004R or TH2004R? (cchristo)
 

I only know from what folks tell me, but if your not going to race or run it too hard the 200r4 is a nice behaving transmission! :chevy

Re: TH7004R or TH2004R? (cchristo)
 

IMO either tranny will be a good choice. Do you know your rear axle ratio, this could help in choosing one over the other :) .

Re: TH7004R or TH2004R? (SmokedTires)
 

It has the stock rear so it "should" be 3.55:1. It would be nice to feel a few more G's from the stop light but keeping my RPM at a reasonable level at 85 - 90 mph is more important to me.


[Modified by cchristo, 1:27 AM 2/5/2003]

Re: TH7004R or TH2004R? (cchristo)
 

It would be my choice for an overdrive in a 80 model. It is same length as TH350,uses same yoke and with some persuasion you can get the cooling lines to bolt up. Most important thing is to get the TV cable connected correctly to the carb linkage. Call Steve Holmes at Bowtie Overdrive, he'll probably agree that you can get by with a stage 1 (mild street version) and Bowtie has the correct TV linkage adapter for your carb.

Re: TH7004R or TH2004R? (cchristo)
 

I just started to do this I bought the 2004R and rebulit it withthe upgrades to bbeef it up I installed the transgo kit, red eagle steel, servo, pump kit, spring kit
this is going behinde a 383 stroker motor with 373 rear.
the trans isn't in yet. a yoke fits from the turbo 350.
Yhe stall i plann on is a 2800 lock -up

Re: TH7004R or TH2004R? (cchristo)
 

The 200R4 has better gear spacing than the 700R4 & was used in the GN & MC SS.

Re: TH7004R or TH2004R? (Ganey)
 

Like Ganey said.. better gear spacing for the 200-4R. Not to mention you see these things living up behind 10-second Grand Nationals all the time, so it's not like they can't handle some power being put through them.

Re: TH7004R or TH2004R? (Ganey)
 

Thanks for the info I did not know that

Re: TH7004R or TH2004R? (cchristo)
 

If you go with Bowtie, spend the extra $150 to get the Level 2 tranny. Steve Holmes told me they don't make any extra profit on that unit -- that's just the difference in cost of the heavy-duty parts they install. It's cheap piece of mind.

Re: TH7004R or TH2004R? (cchristo)
 

Thanks for the info guys. By the sound of it the 200 is a better choice, but both seem to be very comparable. I guess It will boil down to cost in the end.

Re: TH7004R or TH2004R? (cchristo)
 

Nope. They cost the same...

Re: TH7004R or TH2004R? (page62)
 

Thanks to the Turbo Buick guys the 2004R has come a long way. They had no choice but to develop a better 200 since the 700 is a chevy block only pattern. All 200's are dual pattern and will fit chev pont buick olds and caddy blocks. Ive been running a 200 for a good while now and am totally satisfied with it. Would do it exactly the same again. 1st and 2nd gear ratio are much closer on the 200. Also overdrive is a little bit higher. .70 od on the 700, .67 od on the 200. If you search around the web its easy to find all the ratios of both trannys to compare the difference. I cant quite remember them off the top of my head. I would strongly recomend the 2004R.

Re: TH7004R or TH2004R? (cchristo)
 

I went from a TH400 with a 3.08 rear, to the 2004R with a 3.90 rear. Totally changed the car obviously. Just out of direct expierence the 3.90 is a great choice to combine with the 2004R. I run a 26" tire and on a 1/4 mile full throttle run it goes about as follows. I shift @5500rpm. 1st gear takes me out to about 35 to 40 mph. 2nd gear takes me out to about 70 to 75mph. I finish the 1/4 at just over 100mph, just below 5000rpm in 3rd. My cruise rpm in 4th with convertor locked is 2250rpm@65mph. The 3.90 rear turned out to be a great choice for my moderatly warmed 350 mill.

Re: TH7004R or TH2004R? (cchristo)
 

Chris, like you, I drive mine daily and it is close to stock with only a slight more cam than stock. I put a 200-R4 out of a Cad in mine. I believe your Vette should have a 350Th in it so you will have to move your trans mount and get a bracket to mount the TV cable to the carb. Most everything else will change over easily. My trans is stock with only a B&M shift kit and I have driven it dailty for over three years now with no problems. You will enjoy the difference. Hreshey :chevy

Re: TH7004R or TH2004R? (Hershey)
 

Good thread, However I have a question. Is there a preferable donar vehicle or year model to obtain a 200-R from? I would like to put one in my El Camino along with a 12 bolt 410 pos I have my eye on. Thanks JIM

Re: TH7004R or TH2004R? (cchristo)
 

Great info guys, looks like the 200 is the way to go. I'll start seriously shopping around and hopefully have it in this spring.

For those of you who have the 200, what stall speed do you have with your converter? Keeping in mind that mine is used as a spirited daily driver. Tires are too expensive for me to just paint the streets with them.

I'll be doing another cross country in it again this June. It should be nice to get better than 12-14 mpg. With all the gas savings, maybe I can afford some more performance enhancers like a set of fuzzy dice or maybe even a little TV screen in the back of the headrests? :D

Re: TH7004R or TH2004R? (cchristo)
 

Choice of a Torque convertor is really a function of what type of cam you have. I've heard that the stall speed should be roughly a 1000 rpms below the start of your torque band. If your engine is going toward max torque at 3000 to 3200 rpm, then a good stall would be a 2000-2200 stall.
This might be a little simplistic, but it's what I used to choose my stall convertor. It is working out fine for me.
PS Whatever tranny you go with add a extra tranny cooler, get as big a cooler as you can fit in your car. It will help a great deal with tranny life, and is especially necessary with a higher than normal stall TC.

Re: TH7004R or TH2004R? (cchristo)
 

2200 stall here.

Actually the Buick GN's are the best doner for a 2004R. They have a specialized valve body. They are rare and hard to find. A rebuildable core is worth $600. Other than that I believe the later year 200's are good. From any vehicle 1986 and beyond.

Looking for anyone who has put a 200 4R in a C1 to replace a PG. My dad has a 1961 with an iron PG and he wants more modern gears.

Looking for parts list, tips, how-to, etc.

Dad is an experienced mechanic and restorer but wants to do this with minimum of hassle and modification.

Thanks!

Larry