Posted for "Tom Gourley" <tom.gourley@verizon.net>:

 I would also investigate Lycoming IO-540 options, both parallel valve and
angle valve.  Besides Performance Engines I would also talk to Lycon in
Visalia, CA (www.lycon.com). They rebuild Lycoming and Continental engines of
all types and do certified engines as well as experimental.  They can build
you a vanilla engine or pump up the horsepower with higher compresion and blue
printing.  I have friends who have used their engines in certified and
experimental aircraft.  They all report that Lycon's service after the sale is
outstanding.
 
 Tom Gourley
 Legacy #122
 Still building