shimming hydraulic roller lifters solid

Other than the expense, why not just get some solid rollers? They offer significant weight savings over the longer bodies of the hydraulic rollers. Yeah, you have to get longer pushrods, but it is still gets you a lighter weight valvetrain overall.
It's the expense of course, and it is a bit of old time hot-rodding. Making something work where it was not originally intended. Good solid roller lifters are very expensive compared to the OEM roller or a decent flat tappet. Not sure how much different they are in weight but you wouldn't have the link bars on the OEM type