vacuum line attachment point help please- 380SL

While working towards removing my engine I found an undocumented detached vacuum hose and I am unable to figure out where it goes. I have been keeping notes and labeling some things but I don't remember even detaching this one! Hope the image is helpful. The line inquestion is gray and comes out of a 3 into 1 connection behind the brake booster. It runs along the firewall to the passenger's side and has a 6 inch section of rubber hose on the end. It must attach somewhere at the rear passenger's side of the manifold, but I can't see where. Would someone be kind enough to have a look at theirs and tell me where it attaches? Thanks.

Randy

Find the line that goes to the tranny. I think it tees off that line at the manifold.
Don

Sure enough, after reading your post I went back and opened the envelope with the fitting that attaches the transmission vacuum line to the intake and there is a nipple on it as well. The rubber hose on the end of the gray line attaches there. Thanks for you help.

Randy

Randy, let me know how you make out on the engine removeal, as I think I'll be doing mine this winter. I have a front seal transmission leak and after looking things over, I think it's just as easy to pull the whole unit, It'll give me a chance to repair some oil leaks in that area and do some detailing also.
Thanks, Don

Did you see my post in the Tech Forum concerning the decision to not remove them as a unit? I also posted the steps I used to remove the transmission- not a terrible job. I now have the electrical connections detached (except for the sensor at the crank pulley) as well as the vacuum connections. I work on it when I have time. Still have the fuel and AC lines to deal with before lifting it out. Stayed tuned.

Randy