Clearance issue with Harland Sharp roller rockers

a 292 isky is a BIG cam bigger than a 293 MP as far as duration is concerned
but in reality not much lift/ area for that much duration
good news is that they rev well and are easy on the valve springs
you do need to talk with mike read his 4 tech articles on his website
do not b surprised if your guides and vj are shot
what springs and diameter
you could switch to beehives but that does not solve the real problem (geometery)