Ok, lets talk about performance street driving with a tranny that has OD capability. Would like it to perform at the road coarse and drag strip too. Needs to handle 700 HP launches on slicks and shift smooth at 6500 R's. Thinking stick but an automatic could do it as well but there is that weight penalty. I'm concerned about weight but more concerned about having fun reliably. Modifying my e body tunnel is not an issue.

Damon

Choices are many but I think a T56 Magnum or a 727 with a gear vendors on the back would be my picks. I love my Viper T56 but I cannot confirm nor deny its ability for a 6500 rpm shift, yet.

T56 Magnum. Nothing wrong with 4 or 5 speed, but my other car has a 6 speed and I wouldn't have been happy

The T56 Magnums are great choices for sure. Not sure if it would help but since my block also has a GM bellhousing bolt pattern I might have some extra flexibility. I really like the 1st and second overdrive gearing options with the T56. I don't have a handle on the time investment yet though. The fab work is a concern since I won't be doing it myself.

Damon

I'll second the T56, though 700 HP and slicks may kill it after a while. The GM bellhousing pattern opens up more options. 6L80 or whatever the strong auto trans is could be an option. If using the 6 speed, make sure you can really use the 6th gear (especially if it's one of the .50 overdrive models). Tire height, rear gear, cam selection and so on can make 6th almost unuseable in a lot of cars because 6th drops the RPM and lugs the engine so hard.

I have 3.91s in my car with a 26" tall tire. With the cam in my 440, it doesn't "clean up" until about 1900 RPM. So if I lock the converter (47RE) any speed lower than 2000, it's not happy. Pretty much I have the converter unlocked until about 50-55mph. That's with a .69 overdrive. With a .50 overdrive I doubt I could cruise with the converter locked up until about 75-80mph. In my car, a 6 speed would be a waste of money unless I changed the cam out to something that has a wider powerband or a shorter tire or 4.56's.

Just something to think about...

Actually what you need is a T56 Magnum and then send it to RS Gear so they can make it a Transzilla which is supposed to take a million hp/tq haha!
It costs like $10k though for the trans

The Magnum is rated for 700 ft/lbs which is the highest rating of any current manual that you can buy TODAY.

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Would like it to perform at the road coarse

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Automatics don't work well on road a course.

I can't speak for it in a light car, but I drove an '09 chevy with the 6l80e and that transmission was awesome. Kept that little 5.3 in its powerband all the time and it shifted quickly and also held the gears well when needed. If I ever get the money to do so I'm yanking the 4.3 out of my ZR2 GMC Sonoma and putting an LS v8 with the 6l80e in it.

My 727 has been perfect and bullet-proof in all competition events... manual over-ride (simple shift kit) allows full control at any speed... upshift, downshift at any time and not missing that shift. Sure, manual stick-shift trannys are more fun -- I've owned/driven and raced both in road course and autocross. The skill of the driver (aka "the nut behind the wheel") will make the biggest difference in a competition event. I figure.. it's whatever your car has... and master it.

Mitch, am I incorrectly reading something into your on track at speed pic that has "wrong way" in the foreground?

JCC... picture could have been cropped... that sign is at the track to prevent people from re-entering the track on the pit lane and thus going head-on with coming traffic.

No matter how you break it down, even with modifying the trans cross member...the T56Magnum is the way to go.

I want a TKO600, but the limitations in tq handling make it not up to the task for my future goals. I need to keep my 833 and keep 3.23-3.55 gears in it til I can put the car down again for a T56.

I have talked with John Cope some and his recommendation for an auto is the 4I80e trans. The 6I80e can do it as well but the 4I80e is lighter and can be built for 1000+ hp. I don't know what if any trans tunnel work is needed though just yet.

Surprised someone has not mentioned the Passion 5 speed yet. I guess the power handling is an unknown at this point too.

Old motor has FI and so will the new combo. Thinking it will handle the lower rpm's on a cruise if the T56 is in 6th. I didn't think about that point though. 528 cubes with fully ported RPM's and 11:1 cr. Cam is on the large side with lift about .7 on the intake. Duration is reasonable in the 264 range.

Damon

If the T56 magnum is around $3000 what in the world are they doing to it to make the price $10,000 using some parts out of unobtanium?

http://www.ddperformance.com/magnum.html

How much longer is the T56 vs an 833 and how much does that change the driveshaft angle that some people mention is not a good thing when adding either a gear vendors on the tail of a 727 or installing a Tremec 5 or 6 speed trans?

My T56 sits at the factory angle. Length is a little longer than an 833. I scored mine for a good price. The Magnums have wider beefier gears,an internal oil pump,dual speedo outputs and multiple shifter locations among other thing. The trans in my car is the best of the factory T56 derived pre-tr6060. 08 and newer Vipers use the TR6060 which is basically a T56 Magnum but without the multiple shift/speedo options.

I haven't got my SS700 back from Keisler, but it did shift pretty good before I sent it back for the 5th gear issue. They haven't told me why it would come out of 5th? They sent the transmission to Legend gear and transmission to have it checked out. I think they are close to releasing a new tailshaft housing for the Mopar transmissions, so the speedometer cable does not come out at the same point of the torsen bar crossmember like the current version.

I have a 6L90E in my CTS-V with 720 whp/710wtq and have abused it for about 20k miles - and it's completely STOCK. No aftermarket converter nothing and it runs flawlessly. I'd take advantages of that GM bell housing.

BZ