I can't say for sure if the holes are 4 inches or not, but they had gaskets just for that. It has been almost 40 years since I did the same thing to my Demon. I bought the gaskets that were made for the holes. I believe the holes were cut so they missed the cross bracing under the hood. Not sure but I think they can only go in between the bracing, so, I don't think there was an exact measurement taken, just so it fit in the space. Now that doesn't mean mine were in the right place, but they were over top of the carb. Hope that helps.