Is it worth putting in a 427 side oiler?

Keep in mind the 40 was designed for the small block motor, lighter, cooler, sounds better and won’t blister your paint.
which 40 are you refuring to? The Lola GT mk6? Or anything between the Lola and the GT40 mk5?
GT40s won races with the big block FE where the small block 289 all failed.
It was a FIA decision to end the big cubic inches to a 302 max where Ford desided to sell the program to JWA. Where JWA went on with the 917s to win some more races.