Some 2004R help?

[Doober]

Greetings I've been somewhat of a lurker, thought I'd register & ask on the site where people typically put the most power through these transmissions I have an '81 Malibu that I plan to put on the road for the summer and want to put a 2004R in. Unfortunately I don't have the funds to buy a rebuilt unit, so I'll be getting a junkyard trans. I've just read through WE4's thread on strengthening, lots of good info there I'll be building a mild 350 (probably 300hp or so) and plan on running somewhere between 3.23 and 3.73 gears. My questions are:

• What are your recommendations on upgrades/changes to the servo, governor, and valvebody for a street-driven car with this trans?
• How involved is installing a shift kit, etc. on the valvebody... and
• I seem to remember seeing something about making a change/changes having to do with the throttle valve, should I do that here as well?
• What vehicles (outside the G-Body) did the 2004R come in, and is there a desirable model/year to use?

Thanks in advance

 

[bison]

There are a few units you should start with. the BR, BQ, CZ, KZ and a few others. They are from high performance g-bodies. TR's, MCSS, 442. They are the best starting point for various reasons such as the vb and governor circuit calibrations. Preferably a BR. It has the largest servo of them all from the factory. There are other decent ones but those are what you should look for. The servos are cheap used and could be put in any one of the other units mentioned. Shifts recalibration kits are easily installed with the trans on the bench and everything that is needed comes with them if you buy from a vendor on this board. Boost valves, seperator plates, vb springs, hole sizes, and servo adjustment are all mentioned in them. You will be leaving the throttle valve alone in most instances. Just checking it for free movement. There are often cheap high performance 200-4R's in the parts for sale section here.

 

[Doober]

Thanks for the info I know of a Monte SS at a local yard that still has the trans (far as I can remember anyway). Finding anything outside that code trans around here is laughable, though G-Bodies are plentiful in this area. I've never rebuilt a trans, though I worked at a trans shop for a short while, so I've torn them down and have an idea of what the innards look like (I personally wouldn't go past the valvebody though). Are the valvebodies pretty easy to work on as far as a first timer goes? I remember servos are fairly easy to change, would I need to worry about the governor at all? This would also be in a non-computer-controlled setup, so would I be looking at some sort of lockup kit for the convertor?

 

[bison]

Id get CK's book. You will not have very good luck pulling it apart and putting it back together without it. There are many things that could be overlooked. The vb is easy to work on. You could go non lockup with a non locking converter and pump mods which are easy or you could retain the lockup. You need a lockup kit to do so. You wont need to touch the governor circuit. It will shift at around 5400 with the stock MCSS calibration.