For the most part I use the M/W unit as is has the most bolt flange options out there. Don Long made the best ones out there for a time and was a standard in the fuel ranks, However his stubborness in his manufactering process made them difficult and expensive to make. When Don stopped the production, Ken Cox started to make them with a different machining process and knocked them out with the same quality and equal finnish and fitment for less money, But when Ken died so did SPE