Well here goes-------shorter pushrods?????? The fe rocker shafts are in the correct place for stock length valve stems so the geometry is correct unless you have a very high lift cam and/or different length valve stems.I didn't catch it whether this is hyd or solid lifters? If hydraulic you will need to be within a certain range on lifter plunger travel so pushrod/ tappet length becomes critical choices.Sometimes just the use of lash caps will keep you in the needed operating range.

FE oiling system---kind of unique system with some charertists? that you won't see anywhere else----front sump/oil pump(issues with hard leaving wheel standing drag launches) oil pressure bypass valve is at rear of main galley insuring that whole system sees desired pressure(relief valve in pump mainly for cold startup to protect blowing oil filter) lifter galley(after they came out with hydraulics late 1958) fed from two restricted passages between sides near end of main galley.Upper rocker shaft ass fed from #2 and #4 cam bearing bore up to a sideways passage ( uggg) to rocker stand around bolt --oil was directed back toward lifter areas by drain/splash shields that had drip channels to direct oil return to oil tappet tops/lower pushrod ends. System was prone to sludge buildup in the little sideways passage between block/head if oil/filter wasn't changed often--------remember that in late 50s oil was non detergent and sludging was common------