The belt mounting tabs that Willans uses, are so tough, that it broke a Whitney punch one time when someone in my shop was trying to enlarge the hole...
We have the same races here in SEDIV... a "regular" Major and Regional.. at the same time/weekend on the same course - all on track at the same time....
If you want to avoid drilling more holes in your chassis, these are ideal to match and drill your new pan depending on hole size. Worth every penny,...