im looking to get a used 2004r from a junkyard for cheap and have my tranny guy do a build up. whats a good year to look for? also, they're not electronic right? or do i have to buy some expensive controller to get it to work? im hoping its as smooth as my 700r4...

I'd look for 86 and up.
The transmission application tag is located on the passenger side rear of the transmission on the case just above & forward of the trans mount.

1982-1985 transmissions use a two letter code on the tag & 1986-1990 transmissions use a three letter code with an "F" at the end of the code {there may be other letters but all the 86-90 transmissions I've checked have an "F"}.

1982-85 transmissions use a 13 digit numbering system to show what it is & when it was built. These numbers are on the bottom of the transmission tag below the letter code {EXAMPLE: 123 2T85CQ1234}. The first three digits are the Julian date {the date the transmission was built, julian date is the start of trans production so 001 would not be january 1st. The 4th digit is the Plant Shift the transmission was built {1=1st shift; 2=2nd shift; 3=3rd shift}. The 5th digit may be a letter or number & is the code for the Hydramatic plant that the trans was built at. The 6th & 7th digits are the model year of the vehicle the trans was originally installed in. The 8th and 9th digits are the two letter code of the transmission & denotes internal parts & valve body calibration of the unit. The 10th through 13th digits is the serial number of the unit.

1986-1990 transmissions use a 15 digit numbering system {EXAMPLE: 9 123 2T86CZF 1234}. The 1st digit is the Calender year the unit was built. The 2nd,3rd, & 4th digits are the Julian Date {see above}. The 5th digit is the Plant Shift the trans was built. The 6th digit is the Hydramatic plant the trans was built at. The 7th & 8th digits are the model year of the vehicle the trans was installed in. The 9th & 10th digits are the two letter code of the transmission & denotes internal parts & valve body calibration of the unit. The 11th digit is the letter "F". This denotes that the trans is a 200-4R {GM decided to add a third letter to the code that will show what transmission family it is, 200C = "B", 200-4R = "F", 700-R4 = "M", etc...}. The last 4 numbers are the serial number of the unit.

here, these might help...

http://www.layitlow.com/forums/index.php?showtopic=277910

http://www.chevelles.com/forums/showthread.php?t=171433&highlight=billet+forward+drum

http://www.chevelles.com/forums/showthread.php?t=69005&highlight=2004r

http://www.hotrodders.com/forum/tranny-pickle-200-4r-700r4-133627.html
http://forums.corvetteforum.com/c3-tech-performance/2238216-need-advice-on-bto-200-4r-install-come-on-in.html

http://www.chevyhiperformance.com/techarticles/46278_automatic_transmission_overdrive_install/index.html

http://www.carforums.net/showthread.php?t=74799

Where are you at in Texas?

Depending on your combo, your tranny guy needs to be very familiar with the specifics of the 200-4R. On serious combos you don't just use good parts and put them together.

Year isn't critical, you will replace all the parts that need upgrading (pump rotor and guide, sun shell, stator tube, low planet washer/bearing, servo) no matter what year it started as.

its going in a rebuilt 307 daily driver, we're talking maybe 260hp. i just want stage II shift kit and all the important upgrades. my guy is very familiar, he did my 700r4 thats behind 500hp. been running it for 30,000 miles. so i take it the 86-90 15 digit is better?

i just want stage II shift kit and all the important upgrades. my guy is very familiar, he did my 700r4 thats behind 500hp.
Just because he as successful with a 700-R4 doesn't mean much on the 200-4R. It's a totally different animal and although they share some parts and principles of operation, what works on one doesn't necessarily work on another.
260 HP shouldn't be a big issue though, a pretty much stock one with the right valve body mods, an improved servo, and properly assembled should work.

The reason I ask is because I specialize in the 200-4Rs and have two built ready to go (3 actually, but one is shipping this week).
I have one I built for a TC member for a 600 HP comob who failed to send a deposit and seems to have left me hanging with over $2200 invested in parts. It's for sale.

Another mild one for a combo like yours, improved servo, valve body mods, etc.

I specialize in the 200-4Rs. I have them successfully running in 10 second Grand Nationals.
I'm also in Texas.

Hey jake...not trying to hijack the thread, but can you send me a pm with info and a price on the 2004R you are selling? I have a good core I am considering rebuilding myself, but if it's the right price, it would definitely save me some time.

Thanks,
John