Engine paint recommendations

[Daubs]

Been searching the forums for tips on painting my engine. I realize that prep is [/B]very important.[/B] Make sure completely clean and dry. Couple of quesitons for the pros:

1. This is a GM crate engine that is painted black. Should I rough up the black paint with sandpaper or wire brush before putting on the GM orange? (obviously clean the engine after sanding / wire brushing). Or just hit her with orange.

2. Paint recommendations? I've seen Duplicolor high temp paint at local parts store (500 degree paint), and Eastwood carries some engine enamel (300 degree). POR-15 makes engine paint, but will it work well without POR-15 base coat? (and if I POR-15 my engine, will I be able to remove head bolts...I've heard that stuff dries rock hard).

Or is there other brand of engine paint anyone can recommend? Thanks, D.