Holley 1850 fuel transfer tube seals??

I've rebuilt literally hundreds of 1850's, never had a problem with the O rings...
But there's a trick to installing them..... Don't push them fully on the tube or seat them fully in the cavity... Just barely start them on the tube then insert the tube into the cavity.... That way the O ring rolls due to contact on the inside & outside... If you just fully seat the O ring they often get pinched & leak...