garys 68

iTrader: (1)

I'm looking to do an LS swap in a Mercedes 380SL. One of the issues in this swap is the tunnel size. The Mercedes tunnel is pretty small behind the bellhousing, and there are apparently structural elements that are difficult to modify there.
I will be moving the motor forward a couple inches for oil pan clearance, so that will help. I can get by without an OD since the later SLs had a diff ratio in the 2.4 to 2.2 ratio, so a th350 would be a possibility.
So my question is with transmissions that are relatively easy to bolt to an LS, which have the smallest body behind the bellhousing?
I've found diagrams. but none have the kind of detail in that area.

mrvedit

This site might help you:
http://www.tciauto.com/tc/trans-dim/

I only have a 4L60E case handy for measuring.
The critical dimension for you is probably the width. Most of a 4L60E is only 9" wide; it expands at the very bottom for the valve body to about 12.5".
It also expands at the very front for the bell housing to about 11.5".

With a rear ratio of 2.4, you will also want the lowest possible 1st gear.
According to: http://www.chevymania.com/tech/trans-ratios.htm
A Th350 is only 2.52; a 200r4 is 2.74 and a 4L60E is 3.06

I suspect that higher ratio rears are available for your car. What year is your 380SL? (Long time ago I had a '69 280SL that I inherited from my father.)

garys 68

iTrader: (1)

I have not bought one yet, just doing my homework first. Pre 81 diffs were about 3.3:1, then 2.47 after that. I hear the 500SL were slightly lower.
My plan was a DD with a 6.0 LQ or LY, so I could make do with a low numeric 1st gear.

mrvedit

I'm sure you have researched this thoroughly, but a 2.47 rear ratio with a small 3.8l engine seems unlikely. According to this site:
http://www.oursl.com/research/data/o...-380-560sl.htm

the rear ratio is 3.46 and the 1st gear ratio is 3.98, which I would expect with that engine.

And this site says the rear ratio on a 380SL is 3.27:
http://www.uniquecarsandparts.com.au...ifications.htm

It is not hard to determine the ratio. With the rear wheels up, trans in neutral, block one wheel and count how many revolutions of the driveshaft it takes for one revolution of the other rear wheel. (Sorry if this is all obvious to you.)

garys 68

iTrader: (1)

pre 81 was 3.27, after that was 2.47. I've found a few sources confirming. I would actually prefer a 3.27 and a 4L60e but most have indicated the 4L60 is too big for the tunnel. I was hoping a th350 was narrower in the upper section.
IIRC GM used to put th350s and 2.41 in G body cars in the early 80s. So might work of if it fits.

http://www.partrequest.com/auto_part...des-benz/380sl

I have heard all the 380, 450, 560sl diffs are interchangeable so that would give the possibilities of 3.27, 3.08, 2.72, 2.47, and 2.27