What is the max lift on stock L98 cast iron heads?

 

I use to run a compcam with .480 lift on stock 89 heads.I would NOT try running anything higher.

 

I've got a set of .525" valve springs, I could use those to replace the stock springs

 

Its not just the springs the retainers could hit the valve seals too.What cam are you looking at and whats your set up?

 

XR269HR or XR276HR, leaning towards the XR276 cause it's fitting the mods I've got and getting. SLP Headers, LS6 injectors, Stealth Ram, and Hooker Catback. Also a 3000 stall.

 

.46 or so is about the limit of pull out studs. .44 or so is the limit on factory springs, if they have any use or age on them it's time to replace them anyway.

 

Since you're already replacing the camshaft, you might as well maximize the setup by working the heads a little. You need to machine the guides to clear the retainers regardless of what elses you do, so the extra cost of enlarging the spring seats and cutting the guides O.D. for positive seals should be negligible - they're already set up to cut on center over the top of the guide anyway - and can use one cutter for the whole operation.

If you're really planning ahead, you can have them flip the head and machine for 2.02/1.60 valves, then run a boring head down in the valve bowls to open them enough to take advantage of the larger valves. The last time I did this it was only another $65 for the valve and bowl work. Of course, the new valves will set you back another $160 or so, but it's a one-time cost.

Oh - are you still using the TPI? Never mind.