Hi all. I've been pouring over threads on this forum and the rest of the Internet as well in order to figure out how to lower the cruising RPMs on my car. I have 3.73 on the rear axle and a TH400 gearbox (stock as far as I know). One of the guys I share garage space with has 4.54 or (something insane like that) on his pickup. He solved that by installing "a 400 with overdrive" which I assume is the 4L80E. Now, looking around this forum almost everyone recommends the 200-4R if you want to lower the revs and still be able to be quick out of the gate. At the same time I've read that you need to either find a good quality build of the 200-4R (around 1986?) or have one custom built in order for it to manage the torque of a BBB. The 4L80E is as far as I can tell a lot stronger than the 200-4R but at the same time almost twice as expensive. Now, the guy I mentioned earlier sells car parts for a living so he might be able to get me a good deal on a 4L80E but I'm wondering if it's overkill for a close to stock 455. Another advantage of the 200-4R is that it seems to be very easy to install into my -72 GS, I've read nothing about installing a 4L80E into an older Buick. Money is an issue of course but at the same time so is performance as I don't want the gearbox to be too weak. Any thoughts on this? o No: Update: I did a proper search on this forum ( ou: ) and found some info on the 4L80E - mostly that it's heavy and eats up my HP. My question still stands though - would it be an option compared to a 200-4R?
Have you ever considered keeping the strong TH400 and adding a gearvendors overdrive? This combo will also be able to handle higher HP-levels in the future plus it gives you the equivalent of 6 gears wich should help acceleration a lot. The 480LE is the gearbox from the vette and should be able to take some abuse....from what i know a 2004R has to be upgraded to survive the torque of a bigblock....and believe me: sooner or later you want more power... If you dont have the money right now why not cheap out and just change the gears to something like a 3.00??? Since your engine is stock it will not be a racer anyway and the driveability will be much better....plus you save tons of gas. And when you have the cash you do it right. If you buy something halfbaked now you will have to replace it sooner or later and then you pay twice.
I wouldn't do it... we ate up 4 4L80's (professionally built)... behind a 650 hp motor...switched to the th400..good to go....swap gears or get the gear vendors unit...
Thanks for the replies. I've been able to get more info on the 4L80E after my initial post and I'll KISS for this car and go with a lower gear rear axle. I know the TH400 is the best option for this engine but I kinda wanted to eat the cake (sane cruising RPM's) and keep it (smoke some ricers at the red light at the same time. The Gear Vendors overdrive would be nice but it's too expensive. And it's not like I need another excuse to spend time and money right now...
One question....are you going to be doing all(or at least a majority) of the work yourself or are you going to have someone else build the 200-4R for 'ya? o No: I say if you're going to have the 200-4R built by somebody else, then it would probably be just as cheap or possibly even cheaper to just take your TH-400 out, rebuild it w/ a decent shift kit and throw in the Gear Vendors O/D. Just depends on how you really have it planned, i.e. if you're doing the work yourself, you could save some time by just rebuilding the 200-4R and beefing it up than to have to rebuild the TH-400 and put the shift kit, O/D, and rebuild kit but even then, in the long run it might cost the same or be cheaper to go one route or another. Also another thing you should do is get estimates from places that have 200-4R's and see which ones are cheapest, and if you can't get a good deal on one, there again, as long as there is nothing wrong w/ the trans. you have, the best thing to do would probably be rebuild it, add shift kit, and add overdrive as well and you might be surprised, actually! :Smarty: I haven't done this myself, but from researching and having buddies that have been through the same stage that you're at, I think i've gained a little bit in the noggen along the way. :Smarty: Good Luck! :TU: P.S. I know I just may have confused you in the worst way possible, but just do some local searching, see what you can come up with, get the estimates down, and see if you can match the results w/ what it would cost to get your TH-400 built up w/ all the goodies mentioned, then you can start working from there! :TU:
The BBB has lots of torque and you'll be fine with a 3.08 or something like that. While the old 3.73 rear end is out you can build it up and save up for a gear vendors overdrive and motor upgrades.
Well, as money is more of an issue than time I would have to do it myself but seeing as time is also an issue the most rational solution right now is a 3.08 rear axle. I'll get from A to B fast enough with that ratio as well. This is also my first muscle car which means that I need to keep things as simple as possible right now and gradually increase the difficulty. I have a lot of neat ideas for other cars down the line, many years from now. That said, I do have to tear down my engine in order to replace my main and/or rod bearings which I guess is enough work for one winter...
Wierd how no one has mentioned this yet. If revs are a concern, go with the lower rear end. I would recommend staying away from the 2:56. The revs were a little TOO low in my 71 skylark 350/350. I didnt need 3rd gear to do any driving. First gear was fine for under 80 km/h ---> 50mph, and 2nd was good for any highway driving. That being said, when you have the funds, (or even if you can squeeze it in now), i would invest in a switch pitch TH400 to get the torque back. If youre not sure what that is, use the search function, plenty of info on here. Basically its a transmission with two stall speeds in your converter that you can select. So people would run 1500 stall on the low end, and 3000 stall on the high end. For regular driving they would switch on the 1500, and for a hard launch at the track they would choose the 3000. Very popular choice, i bet you could find one for sale here in the for sale section.
Hi Azeem. I have been pondering a rear axle change earlier, the thread is buried somewhere, but the lure of a overdrive was quite tempting (hence this thread). I've come to my senses now though. Another reason that I prefer the rear axle change over the gearbox modification/change is that it's (most likely) a lot easier to get hold of a well built rear axle in Sweden than it is a well built gearbox.
Didnt realize you were in sweeden! It makes sense now why budget and parts availibility is a concern. I think the rear end swap will be the most effective! Like said above youve got plenty of torque, so you can put in a small gear an not worry. Good luck.
4L80-e The 4L80-e was never used in Vette. That was the 4L60-e, the electronic version of the 700-r4. It was however used in 3/4 and 1 ton trucks, and for a good reason. It's strong! If properly rebuilt it should take anything you can throw at it. A few drawbacks though. Like the 400, only worse, it's heavy. Like a 100 lbs. more than a 400 from what I've read. Also they're expensive, both as a core and for parts. They only used it in computer controlled applications, so you'll need one of the aftermarket stand-alone computers to run the shifts and the electronic speedo. BBB's make alot of torque, but if you switch to a 3.08, you'll definately notice it. I know, I've done it. With the 4L80-e you can have the best of both worlds, the extra gear to launch and in overdrive you'll be effectively crusing a 2.80 gear. Plus there are good aftermarket convertors available, so you can have a good launch stall speed and then lock the convertor for cruising. Like the switch pitch, only better. The 200-r4 offers alot of the same benefits like overdrive (2.49 effective final with 3.73) and lock-up convertor. It's WAY lighter too. But with that comes a strength penalty. My 462 murdered 2 of them, including the one I borrowed from my old T-Type. They can be built up to take it, just not a regular rebuild. I spent alot of time researching the O/D tranny's. I decided on the switch pitch 400 because of cost. For either O/D tranny built and ready to rock for your car you are looking at atleast 2,000 or substantially more with the computer for the 4L80-e. Hope this helps. :TU: Todd
One nice thing about the SP400 over the 4L80E is that if you want a loose stall say 3500rpm you have to live with it until overdrive. But with the S/P you can run around in low stall like a stock converter until you wanna launch it. Thats why i am going this way.
I have a 2.56 axle in my 37 street rod powered by a 455 Buick, and it works great! I built it some time ago and was told that the 200-4R would not hold up to a healthy 455. A friend that does transmissions said he could build a 200-4R that would not break, and I had him install one in my 72 GS.455. I have a 3.31 axle in the 72 ,and broke the 200-4R twice before he found the combination. It has worked flawlessly for 3 years now and I LOVE IT. Both cars get the same MPG but the 72 will blow the doors off the 37. The 72 has a little more engine but the gearing is the big difference. :beer
So Joe, what did it end up costing you for the final version of the 200-4r you have in the GS, and how do we contact your friend if we want one built? Does your friend think the trans would last behind a 500HP 455 BBB in a 4400 lb car?
