Technical GM Tappets whats the difference??

Can anybody tell me what the difference is between the GM type HL-30 and HL-26? I need to buy tappets for my project and have found both types, just want to make sure I get the correct ones and to make thing even more complicated everything I find online says they types both fit 49-56 Olds

 

it's the year.



(you can google GM part numbers with a brief description, and find the gmpartswiki page that shows what it fits) http://www.gmpartswiki.com/getpage?pageid=1808

 

THANK YOU SQUIRREL!!!!! for the post and the link to gmpartswiki