It is very simple to identify it as a 428. It has a big A on the block IF it is a 428.
They are all C6ME-A blocks. The 390's have no scratch. The CJ's use a C block. The PI's the A. They all look the same except for the scratch mark.
Some 390's can be bored out to the 4.13 428 bore. Some can not.
The GT500's are date coded differently then the GT350's. The 500's engines are in the 10 to 14 days before the car build and have nothing to do with the Shelby completion dates.
There IS some confusion TO ME on the later builds in that I have seen some C8 engineering numbers with first half of '67 casting dates. No one has been able to SATISFACTORILY explain that as of yet.
Some of the judges here will say emphatically, NO WAY, they were NEVER INSTALLED on the 428PI engines, but I do have some documentation on that they do exist (got the parts) and considering how just pallets of parts being delivered to the engine assembly plant happened, those judges CAN'T prove they were never installed on the 428PI's so I wouldn't automatically dismiss them as wrong.
I've got a C8 timing chain cover AND oil filter adapter with a 2/67 casting dates. Now logic would say that the 428PI uses the big C6 427 balancer and the pointer that matches it only fits on the C3 cover.
I can't disagree with that logic BUT logic doesn't make that correct, or prove anything. That is just "educated speculation" until further notice.
So good luck on assembling your engine without controversy of some sort along the way. There is NO BIBLE on that procedure.
Oh...you might notice NO chassis stamping ID on the "pad" in this picture. It's my block.
Kinda' typical of '67 GT500's, 428's in general and not typical of GT350's. I'm guessing the 428 assembly crew was in rebellion against the stamping mandates similar to the anti-vac folks are today?
Some people question whether or not "late '67 GT500 blocks" exist because they can't find any. Sure they do. Here's one. They just are not very common but then neither are A scratch blocks.
Don't mind me. Controversy is sometimes good. Just think of me as Captain Kaos.