Google ........GMC 270..........then click images. 100 or photos will appear some will be 270 engine. While it will not give part # it will give an idea what others have.
Here is a Stock GMC 228 manifold which I think is a shared part with the 270 ?
[URL=http://s398.photobucket.com/user/showkey_bucket/media/image_zpse7mvvock.jpeg.html]Picture [/url]
Last edited by showkey; 08/03/2016 2:32 AM.
