or you could just buy a crank trigger mount kit from Gessford.
it includes the shortened spacer with provision for mounting the wheel and a bracket that bolts on using the front
oil pan bolts.
As with all engine cost estimates that get posted here, it's hard to get details. What exactly would make that a $20K engine?
$4 for block
$1 for rods and crank
$1 for pistons, rings, fasteners
$1 for intake (conversion @500, intake @500)
$3 for misc parts
So where's the other $10K in expense?