If you were to put an auto tranny behind a 550hp LS7, which tranny would you recommend and builder. Thanks

 

What was it being used for?

 

69 Camaro street car, driven daily if possible but not a DD.

 

Well if you are going that far to it and going daily, i'd try to fab up the 680le for it, 6spd auto would be great.

I'm pretty sure driven sanely it'll hold up as well.

 

First thing I thought about was the 6 speed auto as well.

 

WOW! Actually this is the first I've heard of a 6spd auto, but my research found that they are due out in 07's. Not to go overboard but probably a 4spd OD will do fine. Looking at Monster Tranny 4L65e. Ever hear of Mad Dog or Hughes? What do you think? Thanks

 

If you want to go that route check out Performabuilt. I have heard good things about their built transmissions.

 

I'd look into the price of a 6L80E first. It may end up costing about the same as a built 4L65E, and you get 2 more gears, better performance, better fuel economy, and manual gear selection

 

Ok, good arguement for the 6L80E, where can I find one.

 

try gmpartsdirect. find the parts number for a 6L80E. you can surely get it from gmpartsdirect.

 

^beat me to it. you could also find one from a wrecked car on the cheap. bring it to one of the sponsors here to build it for you if need be

 

A little googling yielded gm part #12491349 ... the price is not bad on gmpartsdirect, if thats it.

 

Went to GMpartsdirect and found that part #, good price $1871. Now I don't want to have to modify the tranny tunnel as I would with the 4l80 thats the reason I like the 4l60. Does anyone know the size/shape of the 6l80. I'm afraid that the 80 in 6l80 corresponds to the 80 in the 4l80 as far as size is concerned. I hope I'm wrong because 6 gears are more fun than 4.

 

From what I've read from a little searching it will physically fit in the tunnel but you will need a different bellhousing and an interface with the computer.

 

The "80" in 4L80E and 6L80E merely refers to the duty rating of the trans. So a 40 (as in 4T40E) is light duty, 60 (as in 4L60E) is medium duty, and 80 is heavy duty. It doesn't mean the 6L80E and 4L80E share any size specs, the 6L80E is a completely new transmission from the ground up.

 

Bellhousing should come with the transmission, never seen an automatic without a bellhousing attached.

As for the computer, it might be possible to reflash the one he has for the new trans, or possibly get a stand alone unit to control it.

 

do a search the 6l80e bellhousing doesn't fit from what I understand. And yes you need some kind of standalone unit or factory interface for the computer

 

Did the search, got specs for the 6l80e, and found some opinions that the 6l80e is lighter than the 4l80 heavier than the 4l60 and size wise somewhere in between. No definite info on if it will fit a 69. Couldn't find bellhousing info. Luna I'd apprecite specific threads if you got em. And yes from what I can gather, the electronics still need to be worked out. I thought I kept up on the conversion stuff since I've been thinking about for a while but the 6l80e was new to me and I'm definitely excited about the possibility of 6 gears, especially a 4.02 1st and a 0.67 6th. WOW I wonder how that will feel with a 3.73 rear. With a my 700R4 I have to shift manually from 1st to 2nd before I'm thru an intersection.

 

You CAN NOT use a 6L80E without the factory harness and computer(s). Nobody makes an after market stand alone transmission controllers for this transmission. This transmission works on a CAN-bus system and the transmission's "computer" is located in the transmission. In order for this unit to work it needs inputs from other "computers" on the network. You would have to take EVERYTHING from a donor car in order to make this work.

 

So you would have to take all the electronics from a a 07 corvette, caddy etc. if I understand correctly. Dang. Ok I'll just manually shift it with my B&M.