This one apparently will seal up the VVT/AFM holes in the lifter valley, I assume I still need to plug them as well?

Gen IV LS NON-AFM DOD Valley Cover Block Off Plate for Chevy GM 5.3L 6.0L 6.2L | eBay
US Warehouse,Fast Delivery! Shipping conditions: Attention: The goods will be shipped from US Delivery time: 3 to 5 working days - Support 30 days return policy - Reply within 24 hours Description: .
www.ebay.com