Alright, thanks for all the responses you guys.

Couple of things I want to consider as a (perhaps) viable Plan-B type approaches:

1) run a different set of valve locks, something that's offset by 0.050" to give me that extra installed height, my only problem so far is that looking at how well the Harland Sharp 1.6 rockers line up with the valve stem I am already a bit off on the exhaust valve since it's a tad shorter than the intake, tossing a lash cap on there brings the geometry back in...unfortunately I can't do lash caps with the offset locks

2) find a different set of pring retainers that actually give me that extra 0.050-075" room, challenge there is that the 930 springs are already pretty wide (1.565") and that's putting the retainer pretty close to the rocker body, I'm worried that trying to find that extra 0.050" room to grow taller just isn't going to happen, I need to toss the rockers back on there and starting measuring closely beyond just eye-balling it

3) find a different set of spring locators that are thinner than the 0.060" set I have right now

Anyways, at least a few options. I tell you though, looking at specs only at the moment the 978 springs do fit in real nice with the goals of the project...so it may be one of these situations where as much as I hate to just spent the extra $$$ on the parts, it may just be the right thing to do here...grrhh!!!