FFR428,
You can put crossbolts in if you want them. It is NOT a home builder job as it requires machining not only the inside, but the outside and making spacers for each side of each main cap.
Personally, I wouldn't bother and here is the reason:
The 428 is not a high rpm engine like a 427...even if it has been built for extra performance. 5,500-6,000 rpm is plenty for it. With that in mind, a well prepared crank and rods, along with some attention to "detailing" the existing
oil passages, will handle what you will likely subject the engine to.
Not to rain on your parade, but 500hp from a 428 is not going to be a very driveable engine, not to mention a lot harder to get than one might think. That will take a lot of compression (12:1 or more) and a VERY aggressive camshaft, along with serious cylinder head/intake mods and race prepared carburetion.
In reality, if you get it to make 400 REAL hp, you will have more than enough to give you the ride of a lifetime and still be able to use pump gas and drive it on the street. Don't let all of the "hp numbers" you read on this site throw you. A lot of it is "book numbers" or just wishful thinking and isn't based on reality.
Great find on the block! They're getting pretty scarce. Enjoy your build.
Al