427 4 bolt block question

[jfkheat]

I finally got home long enough to get the 427 I got off Ebay. I think it may be a 2 bolt block that was converted to 4 bolt. How can I tell if it was a 2 bolt block? It is a 512 block with a cast date of Jan 15 1969. The block was decked at one time so there are no numbers on the pad. I can't find any numbers near the oil filter. Exactly where would they be?
Thanks, James

[Keith Tedford]

The 4 bolt blocks should have the two big pipe plugs above the oil filter boss. These were used for an external oil cooler if required.

[markjohnson]

Keith is correct. Both pipe plugs above the oil filter will large and of the same size. On a two-bolt main, one of the pipe plugs is smaller than the other.

[69L72RS]

Hello James
I sent you two PMs.
I have 11 points that I use to check, if a block is suspect of a 2-bolt/4-bolt switch.

They are not absolute checks but they have saved me from buying converted blocks in the past.

Hope this helps.
Later,
Eric

[Chevy454]

Good stuff, Eric...mind dropping me the same info via PM?

[69L72RS]

I thought 2-bolt blocks had 1 fitting for the oil sender
and 4-bolt blocks had one hole for the sender and a second larger hole for the oil cooler line fitting.
I will try to find a picture to post.

Eric

[jfkheat]

Thanks for the replys. Eric, I will call you shortly. The block has 2 holes by the filter. The one directly above the oil filter is larger that the one that is off to the side.
James

[Kim_Howie]

Sounds like a 4-bolt block

[Stefano]

Aren't those bosses routinely drilled on conversions?

[Don_Lightfoot]

Could this be a picture of one.