[ByronRACE]

There's other block mods you should probably consider if you're going to turn enough rpm where that's a problem, but since it's mostly valvetrain you're addressing, I'd recommend some steel rockers, a jomar girdle, and beefy push rods if you're going to push it. Nothing is going to move around with that stuff. I've had mine to 7500rpm without issue using the above. Solid roller.

Since you're hydraulic roller, you're limited to 6000-6200 rpm anyway, and the lobes are very tame. I question whether or not a girdle is going to be necessary in this application. There's a few hundred (if not thousand) guys that operate 385 series Fords in this RPM band without such things and without issues. Check out the engine build section of 460ford.com. I really don't think I'd spend the money there, but instead buy high quality rockers and beefy pushrods, and the best lifters money can buy...and leave it at that.

Additionally, you may want to ask the question regarding hydraulic retrofit rockers on that forum above. They are not terribly popular due to the resulting valvetrain geometry that causes wear and stability issues in the first place; perhaps that's why your builder is seeking a solution. However, the root of the problem is not that the valvetrain itself is inherently unstable; it's probably due to the geometry that results when you do the hydraulic retrofit. Most of these guys either run solid roller or solid flat, and have good reasons for it. It would be worth a conversation with a few of the guys that do this for a living; Kaase is a great resource if you can get a minute with him on the phone.

When I originally did my build, I was teetering between the hydraulic roller and solid roller, after reading a ton, and asking the question, and getting some very good arguments presented against hydraulic roller, I opted for solid. There are MANY more cam grinds available now for solid roller that have very tame lobe profiles due to the popularity of roller cams in street cars. You may want to consider that path...a very mild lobe and a solid roller lifter gives you RPM capability and will remain very stable only requiring a check/adjustment once a winter on a nice-day-driver type car. You really should be taking a look at the internals and springs once a year anyway...why not adjust the valvetrain while you're there.