i got a 360 with a 40 over bore.....

Most gaskets are made with the largest possible bore for that type. In the LAs case it's 4.10 (4.04+.060). Some MLS ones are for smaller bores but I think you have to order them for a specific bore... More important is the surface finish. MLS gaskets take a very smooth surface on the heads and block or they will leak... Especially when cold and never run. Some shops don't even have the equipment to get them that smooth.