I run the 444 progressive chrome stock in length for the rears, On the front a 2002 front end with race tec springs on my 1992. Side frame braces bolted to the frame at both ends. What a difference from stock . ride is 10 fold better.
My vmax was starting to do the same thing, have you bleed them? Having air in the line was part the problem with mine. Also when was the last time you changed out the dot 4 as it breaks down over time and water can get in over a period of time sitting if in a damp garage. Last but not least is...