I've chosen hyd roller grind RRB1 242-252 for my latest 498" street/strip combo. The recommended springs from the site are 73815. I can't get that spec page to load to check out spring pressures. Was hoping for help, thanks. Tony A. graemlins/clonk.gif

Chevywidow,

I think the 73815 Lunati spring is actually too small for a .600lift roller at 6500 RPM. For a single spring you would go with the 73236 Lunati that is listed. Only problem is the spring seat pocket won't accomodate anything larger that a 1.535" od without machining. I just ran into the same scenario. After plenty of questions, answers and research I wound up using the Comp 925 double spring set. Near ideal for a .580 - .600 hyd roller. 1.510" od , 122# @1.900 installed ht., 350# @ .578" lift {359#@.600 lift}. Also, if you ever have a problem, the risk of losing a valve into the cylinder is eliminated with the dual springs [ the valve will float but won't drop down - unless you broke both springs].

ChevyWidow,

There's nothing wrong with GRN69CHV's answer, I prefer dual spriings to single, every time.
Although I have no part numbers for them yet, I have a number of .600" valve lift BBC hydraulic rollers that work just great.
Master number---seat----.050
UHR11 280 228
UHR14 284 232
UHR12 288 236
UHR15 292 240
UHR16 296 244
UHR13 302 250
All valve lifts are .600", and I generally make them on 112° to 114° LSA....
We have pulled 630 BHP at 5400 out of a 9.2:1 540 on 87-octane, idle around 750-800, using the 288/296HR14.......

UDHarold