I need help !

92 Magnum 360 stock everything except cam, intake , old
crane grind adv
Int 498/274 adv
Exh 512/286 adv
LSA 113
No cam card
It dialed in at those exact numbers

I got the Hughes 1110 spring kit
Springs good to .550
Retainers, locks.

My research led me to believe that with 512 lift there would not be enough clearance between the top of the valve guide and the retainer.

I put it together, and measured several different places, the were all roughly 20 thou.

I'm close to cranking it soon and don't want to have that question mark gnawing on my brain.

I called Hughes today and yesterday spoke to 2 guys, as I had heard the they had manufactured a retainer to provide enough clearance .
When I said "superseded retainer"
It was crickets

the tech guy was supposed to call me back after lunch. Yeah Right.

What's your experience been There ??

Can someone help me out here ?