If you look at the HG pictured at the back of #6 cyl water jacket (between the rear head bolts it has 2 triangular holes instead of Toyota's newer "improved" gasket which has 2 very small round holes. This is why I would use at least an OEM HG. Rings thread Please post: Thoughts on aftermarket piston ring choices for 1FZ-FE rebuild - https://forum.ih8mud.com/threads/please-post-thoughts-on-aftermarket-piston-ring-choices-for-1fz-fe-rebuild.884750/Honestly it is a perfectly fine rebuild kit. OEM is better but that is all solid decent quality parts. I would use oem parts myself but if your on a budget that will work.