I know 2 people that have done LS swaps in their Y-body cars (63 Skylarks) and they found it was not easy, tons of unforeseen fab work, and way more $$ spent than planned. Well even after all is said and done they BOTH have bum steer. Man thats gotta suck. I don't think either 1 would do it again if the opportunity arose. Keith
There is a guy on the board that is parting out a '66 4 door Skylark with a good running sbb 300 that he is planning to sell. I'll find the thread and post a link.
Here it is; http://www.v8buick.com/index.php?threads/66-verde-green-gs-post-coupe.337068/ Not sure how close both yous guys are to each other but sbb 300 are still out there if you decide to go that route.