On a different thread I asked what was involved in upgrading to an overdrive transmission and I was reccomeded either a 700R4 or a 200R4. Which is a better transmission and which would be a better fit for my '64 Electra convertible? Thanks, Larry
The trick with your swap will be an adapter, you will need this with either trans: http://www.transmissionadapters.com/53-66_nailhead.htm Once you have an adapter you can pick either trans. They both have their advantages. I prefer the 2004R mostly because the gear spread is more even.... I am not a big fan of the 7004R because the difference between 1st and second gear is massive. If you do go for a 7004R then look for a 90 or 91 year and one from a V8 car or truck as the V6 versions are weaker. The early 80s 7004R are terrible and they git better my 88 and even better in 90. The stock 7004R is rumored to handle a bit more power than the 2004R however the 2004R has more potential for being upgraded to handle lots of power. The 2004R are great trans, I like them better than the 7004R. Keep in mind either way you go that both trans will require a Throttle valve cable and you will have to buy a braket for the TV cable to mount to the intake manifold and you will have to modify your carb linkage to work with the TV cable. Extreme care must be taken to get the TV cable setup and it is best to take it to a trans shop and have them perform the hyd. line pressure tests to ensure the TV cable is set correctly. Info about the TV cable: http://www.tvmadeez.com/article/index.php Improper TV cable adjustment and or geometry issues are the leading cause of failed 200 or 700 trans, the next reason is from overheating, and the third is from lack of fluid changes. Properly setup both of the trans are good for roughly 200,000 miles before time for a rebuild. This means that dropping in a junkyard trans may or may not work out well for you, might as well buy a trans from a re builder with a warranty. The little things add up with this swap so it is not as cheep as a $200 trans with $50 in parts like some people think. When it comes to the lockup torque converter on these 200 and 700 trans, that is a great feature it allows us to lockup the torque converter 100% when on the highway and around town have a regular stall converter. They work great with a 2500-3000 stall converter which gets the car off the line way better than the stock converter, and then I just use a toggle switch to lockup the trans on the highway.
To help you with your search for info, you'll need to get the nomenclature right - which is confusing thanks to GM. It's 200-4R and 700R4. Devon
Neither trans are rated to handled your car without some better than stock internals. A 200R started out rated for 190 hp, 275 ft -ib engine in a much lighter car.
The 2004r was used in B and C bodies through the 80's so don't say that it can't handle the bigger cars. Everyone assumes they only work in G-bodies, but most of them found nowadays actually came from the big cars and were bolted up to small block V8's.
IMHO put your ST400 back in. It is the Best transmission. By the time you purchase a new trans, have it built to hold up to your Super Wildcat Torque, purchase adapter, figure out how to install and change driveshaft you could be driving and enjoying your beautiful and original Electra convertible. Its probably already got a highway friendly gear, and all the torque in the world to get it going...how long will it take to save the 2-3 mpg vs initial expenditure? I'm all into upgrades that make sense, but this one in particular is bugging me and I'm sorry for the rant like nature of this post... One great thing about the Buick V8 is the low end torque. It allows the combo of V8, st400, highway gear to feel strong taking off and not wind out on the highway. The gear spacing on either newer automatics were designed because the engines don't have the torque to do what the Nailhead does. Thanks,
I am using the 200-4r trans and I think it is great. It has been in there for 5+ years now. My car weighs 3800 with me in it and I race the car on occasion. I run nitrous on it so it can handle the power. I use a manually operated switch for the lock up on the convertor. I can lock up in 3rd or 4th gear. With my 373 gear and locked up on the highway I run at 2200 rpm. I think that trans is in the Grand National so if it works there it will work in yours.
I recall the GN uses a special 200R model trans built to handle its power. Someone who is a GN expert can confirm this or remind me that I am incorrect.
Not really all that special. The turbo cars and some Monte SS and 442's got a different valve body and governor which helped with shifts and line pressures to make it feel firmer and have a bit less slippage under heavy throttle. The rumor is that the last of the 2004r's used in 89 and 90 on the big cars were the strongest. Nobody has actual proof though since everyone rebuilds them before using them.
My main objective was to have low rpms at highway speeds (75 mph). I was looking for about 1800-2000 rpm. Since i have never driven this car and the last time I rode in it I was about 12 years old I have no idea what rpms's these turn at highway speeds. I "might" be jumping the gun with and OD tranmission. that been said...... what kind of RPM's will this car turn at 75 mph? I'm not sure what the gears are but I do know it's a posi.
The best way to tell your gear ratio is by opening up the rear end cover and counting the teeth. Another way to get a rough estimate is by driving at a known speed, recording the RPM, as well as your tire hieght, to find out the gearing. Use the second one down: http://www.ringpinion.com/Calculators/Calc_RPM.aspx
Save yourself the mess / trouble of opening up the cover. Jack up rear so tires are off ground, mark driveshaft, put trans in neutral, turn tire 1 full turn and count the revolutions of the driveshaft. :TU:
You most likely have a 3.07 gear ratio. With a 28in tall tire, you'll be at roughly 2800rpms at 75mph. To get to 2000rpms at 75mph you'll need an OD ratio around .7 or so.
Gear Vendors units require major surgery to the frame to fit on X-frame cars ---------- Post added at 10:31 AM ---------- Previous post was at 10:28 AM ---------- I would look for a 200-4r and adapt it or a '65-'66 Nailhead SP400 (switch pitch 400) which will bolt right on without an adapter and almost act like an OD tranny with the switch pitch converter.
the 700r4 is .70 2004r is .67 ---------- Post added at 08:17 AM ---------- Previous post was at 08:13 AM ---------- the hurst olds and the grand prix 2+2 also had the upscale trans........the strong trans in the 89-90 cars is the police 9c1 caprice 700-r4
Ok, so after much deliberation and compelling arguments to stay stock..... I have decided to go with a 700R4 from monster transmission. The reasons are that I plan on doing a lot of highway driving and I want to get the rpm's down strictly for a nicer comfort level. I am also looking for the extra zip off the line with the lower first gear. I think that with the massive low end torque that the dual quad 425 cid has I won't have any problems cruising on the highway at the lower rpm's. Fuel economy.... c'mon guys..... it's a dual quad 425! As long as I don't LOSE any fuel economy I will be ok but it is not the reason why I would do the conversion I DO have one more question to the guys who have done this conversion in a mid '60's Buick or chev........ how did the shift indicator end up for you? Did you do anything special with it? Thanks for all your help guys, I appreciate all the responses Larry
