A lot of speculation, you'll just need to go out and drop the hammer to see if the springs helped out or not.
IMO, this is the best path for you to take at this point.
I don't feel running solid lifters on a hyd cam in a street car is the right move.
If you want to adjust valves, put a real solid cam in it.
If the std lifters don't work out, I would try some hylift-Johnson B-2330S lifters instead.
If those won't get the motor to rpm high enough for you, then you have to decide if you can live with however high it goes, or try a different cam that would allow the motor to reach the rpm level you're after.
