Pretty common for the higher horsepower engines I do.
Have your heads been worked on at all? The only issue with going with a larger cam is that you can potentially move the powerband out of the range of the cylinder heads. When you shift the curves to the right with a mismatched cam, you lose bottom end and then you lose top end both.
The other issue with a solid roller is the longevity. It's not much of a problem in a "toy car", but even the best solid roller lifters are recommended to be inspected/changed every 7500-10000 miles.
With that being said, I can pull to 6500 with a hydraulic roller and the correct valve springs. Any cam with a curve focused on the mid/upper rpm range will make an engine feel like it's "coming on" harder.
Check out the video of one of my 529ci engines with a hydraulic roller....as you can tell, it wants to come on hard at the end. It's the one at the very bottom of the page.
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