440 rear main seal

I`m getting ready to set the crank in my 440 and I open the rear main seal package only to find that there`s only two semi- circle seals! The two side strips are not included in the kit. When I talked to the fellow that sold me the gasket set, he said the company (making the kits) stopped putting those side pieces in the kits because they leaked. He told me to fill the sides with Ultrablue silicone and let it go like that. Is this the common practice now?