69MyWay

iTrader: (2)

I am putting a LS1 in a 1985 Vette. I am using a trans from a 2001 silverado. I had hoped to bolt on my 700R4 tail housing which has the special mounts cast on and drilled through to mount to the torque arm. It won't fit. It has four bolts and the 4L60E has six.

How do I work around that?

G-Body

iTrader: (4)

I see a couple ways around this.

You could swap on the tailhousing for an 98-02 f-body since it has a torque arm and the mounts on the tailhousing for it. I do not know how you would know if the holes for the torque arm would line up though, unless you had measured one before you started the conversion and set your motor/transmission placement so that the torque arm would be the right lenght.

Or you could do like the B&M TH350 swap kits for the 3rd gen f-bodies do and fabricate a bracket that bolts onto the tailhousing to trans bolts and then goes back to connect to the torque arm.

69MyWay

iTrader: (2)

Here is what I have found.

The Vette housing looks like this:



The 98-02 F-body looks like this:



I see this kit here for converting to a mechanical speedo or something. Although I am not interested in that, there appears to be a 4 to 6 bolt adapter here:



I don't know though if that will through off where it reads the speedo input.

Outside of that, I think you are right about going with a homemade bracket.

The engine and trans was already out and long gone before I started this project, so nothing to measure from.

joelvette

iTrader: (11)

i've got an f-body tailshaft and torque arm mount at home, but i wont be back till the7th. i'm using the conversion setup shown above to get vss for the computer and regular output for the mech speedo in my 73 firebird.

wildmanaaron

iTrader: (10)

Isn't there an easy tailshaft that bolts up to the transmission that you could probably get at the dealer or in a junkyard to use the bottom transmission mount like the older cars used.

(Like the tailshaft conversion pictures shown above?)

69MyWay

iTrader: (2)

The problem is the Vette uses an aluminum torque arm like the F-body that has a pair of bolts that go verticle through the housing and clamp the arm tight to the tail shaft. The trans I have now has the standard horizontal trans mount spot.

Joelvette - Is the F-body bracket the same as the Vette?

joelvette

iTrader: (11)

f-body and vette are not the same, and the f-body one does have the bottom mount for the isolator like the old stuff.

STL2SLO

iTrader: (1)

None of the transmission parts, torque arm, or torque arm brackets off of a Fbody is gonna work on the C4.

69MyWay, I have pulled plenty of trannys out of both the C4 and Fbodys, so I am familiar with both setups.. You are gonna have to find an somebody that makes an adapter for the tailhousing. I know there have been several people that have done the C4/LS1 swap but dont know what trans they are using. Hopefully they will chime in and help..

69MyWay

iTrader: (2)

Doing some more research, I found this:

http://eshop.advanceadapters.com/com...roduct_id=1366



This thing is 1.6" thick and WILL bolt to the 98-up 4L60E and adapt to a 700R4 tail housing. It will require slotting out a bit the torque arm holes to mate up as the final length of the trans will be a tad longer, but the LS1 forces me to slide the engine a tad forward balancing it out within 1/2". The only snag now is getting the speed sensor to go in the right place.

Options here include locating and epoxy setting the LS1/4L60E sensor in place.

My other option is to fabricate a bracket to mount to the arm. That would be less expensive, allow the speed sensor to sit in the right place, but would be weaker than using the correct tail housing.

CHarris

iTrader: (5)

Just use a late C4 tailshaft. Get one from a car that had the 4L60e - any of the LT1 cars should have it. Thats what I used.

69MyWay

iTrader: (2)

Did you use a 98 and up 4L60E with the removeable bellhousing, or a first gen 4L60E?

In my research I have found the late C4 with the first gen 4L60E used the same four bolt rear housing as found on the early C4.

The 98 up has six bolts.

Also...do you have a link to your 91 6.0 LSx Vette build? I would love to see pictures of it.

CHarris

iTrader: (5)

I used a 1st gen 4L60e tailshaft form an automatic corvette- like a 95 or 96. My torque convertor was from Yank and has the LS1 front cover with the lt1 style 4l60E rear cover. It mates the two perfectly.

I've actually had one problem that has been killing me since the install during the spring... The transmission is stuck in limp home mode so it only has P-R-N-3rd. No 1st or 2nd. I think it's a VSS problem so I'm looking into that now.

Here's the build...

http://forums.corvetteforum.com/show...77&forum_id=48

69MyWay

iTrader: (2)

Okay, so you do have the late C4 style 4L60E with the bellhousing that is all one piece to the body of the trans with the exception of the tail shaft.

I have been doing some back-tracking on your threads here and at Corvette Forum. I am very interested in your conversion but I can't open any of the community webshot pages.

Would you mind sending me a pm with your phone number so I could ask you some "been there-done that" questions?

CHarris

iTrader: (5)

Email is a lot better for me... cory@ls2portworks.com