No need for a block guard. If you want todo something beneficial resleeve. If you dont have the money spend the money on a good bore and hone. With forged pistons, forged rods, management (AEM EMS, Hondata, Neptune, Crome, Uberdata), a good tune, larger injectors, etc. Your setup will be good for 350whp. After that it's hard to get more HP with a stock or close to stock LS head without a "large" turbocharger.