lift @ the valve?

Hey guys..putting a 360 together with Indy x heads, prw 1.5 stainless rockers, Hughes cam with 558 lift with 1.5 rockers....last weekend I checked camshaft centerline etc and in the process checked lobe lift and it came out perfect. Tonight I started to check pushrod length and the most lift I could get @ the valve is around 510. Is this normal to lose this much lift?