[FASTASSBIRD]

Originally Posted by caddor38

Thanks for the reply, here is a picture of the main cap. I am assuming this is original 4 bolt main caps since this was a standard bore. It appears to be GM5 A77?

That’s the rear it looks like. I want to see the front cap looking down at the face of the block. Plus their should be a full part number on the cap. I’d have to go look at mine to see what the part number is but legit original 4 bolt blocks used a specific front main cap. In the end all that will tell you is it has the correct caps. Not a definitive answer to it being an original 4 bolt from the factory but certainly helpful info in the argument. Most guys who swap the caps just swap the center caps cause they don’t know better.

[caddor38]

Originally Posted by FASTASSBIRD

That’s the rear it looks like. I want to see the front cap looking down at the face of the block. Plus their should be a full part number on the cap. I’d have to go look at mine to see what the part number is but legit original 4 bolt blocks used a specific front main cap. In the end all that will tell you is it has the correct caps. Not a definitive answer to it being an original 4 bolt from the factory but certainly helpful info in the argument. Most guys who swap the caps just swap the center caps cause they don’t know better.

Here is the number on the cap