what is the better block dart or merlin and why .thanks

allthough i have both,i think the dart is better,more nickel in the casting,it is also a little bit heavier then the merlin.they are both good.

I'm not an engine builder so I can't answer your question, but I think Dart now has the biggest block with their new 765ci monster.

Both are good blocks,I like the dart better the cyclinders are real hard takes a special hone to finish them,i think the rings seal better and lasts a little longer

I prefer the Merlin. The Merlin block has a cleaner casting than the Dart. The biggest thing that I prefer are the main caps. The Merlin has a true billet main cap that is way beefier than the steel Dart caps. I have used both in the past and now I only use the Merlin.
Eddie

it seems the things I like about the merlin, cleaner castings and a little less weight are the things the dart guys don't like. I think you'll find builders using merlin blocks when budget is less of a factor.