Hey,thanks for the pics and nice looking engine.I have an echo 45cc im doing right now so ill have to wait on a 3900 for a little while.I foiund a short block but i dont remeber if it was a 346,3600,or 3900.Ill have to go search it down again.I went to the site also and those prices are at least,if not just a hair cheaper than what the echo dealer close to me sells to me for.For instance,i paid $129.00 for a 24cc short block.But he wanted $99.00 for a cylinder kit.