looking for a replacement engine for my 1976 porsche 911

I would say geta rebuilt that way you know what you have, if not rebuilt there is a porsche dismantler in LA that is always parting out porsches.

http://www.ladismantler.com/parts/977-Used-Porsche-3-2-Engine-Complete

Try Kevin at Randolph Racing in MA. He is constantly rebuilding engines, usually upgrading them at the same time. 781 344 1029

Unless you want to keep the car original you might consider putting in a used engine from a newer Porsche. I believe the 76 had a 2.7 liter and not considered a great engine. The 2.7-liter 911S was so problematic that it was named as one of "Porsche's Deadly Sins" a couple years ago. For almost the same price as a quality rebuild you can buy a used 3.0 (from 1978-1983), 3.2 (from 1983-1989 ) or a newer 3.4-3.6 liter motor for around $5,000. The motor will fit right in, you will have a better engine and your car will be faster!

Check www.mbmotorsportsrepair.com, they always have engines for sale, great prices too.