Good morning gents!

Almost finished restoring my 1985 MCSS (all stock, mostly original), and ran into a snag with the exhaust. I can't seem to source a new front Y Pipe anywhere. After failing with finding stock from the Walker brand (item #40292), I decided to go with a complete Magnaflow stainless setup. I ordered:
-Stainless front y pipe (16451)
-Direct fit cat (93940)
-Stainless cat back (15147)

I received the last 2 items, but the front Y Pipe (item #16451) was cancelled due to out of stock. I then began ordering from nearly 8 online retailers sequentially after each cancelled my order due to lack of stock.

What options do I have to buy a new front Y Pipe? TThanks in advance.

Have an exhaust shop fabricate it.

Your better off building it yourself. The stock Y pipes are very restrictive. Get a length of 2.25 pipe and a 2 in to one 2.25 to 3 inch. Connect to the cat and go from there.
Something like the Flowmaster Y collector Y214300 should get you in the right direction

Edelbrock tes headers come with the y.