Yes Randy that is a pic of my 493 with RAS prepped Isky rockers with RAS shafts and the Hughes hold down kit with studs.
I used the kit from Mancini MREHU7442 and just drove over to the Harland Sharp factory/shop with a head and the rockers and they checked out what I was doing and sold me the spacers and shims for $30.00 I got more shims and spacers than I needed.It's nice they are only about 45 minutes from my house.All you really have to do is measure the space between the rockers and order the proper spacer kit from Mancini.
Gus