rob scott

iTrader: (14)

I just bought a set of dart 225's milled and ported. I'm going to swap them on my 98 in a month or so just making sure I get all the right parts so I can do the swap. I plan on using the GM mls gaskets and wasn't sure if I should use the stock gasket bore size (3.920) or go up in size? If I remember right the gasket sizes were 3.910 and up on the site I was going to order from.

PREDATOR-Z

Gasket should be at least .030 larger bore than the biggest bore you have. (Whether it is cylinder bore or chamber bore).

vettenuts

iTrader: (4)

Dart heads have a wider chamber. As I recall, when I used the Dart 205's I needed the LS2 gasket. That being said, the Dart 225's may have a larger chamber and you should measure the chamber size prior to ordering gaskets. The heads will definitely control the gasket bore in this case.