Please set me straight . Do I have to drill through the heat crossover to activate emissions on the 86 and back heads?The pdf on the Summitt web site under the 58 cc 305 torquer heads states I do.

 

Mine came with the passages open.

I believe it's only the Sportsman IIs that need drilling, but I wouldn't swear to that.

 

I just put a set on my '89 and I was very surprised to see that they came with the exhaust crossovers already drilled and the perimeter valve cover bolt bosses milled down. These two machining operations, as of my last visit to World Castings' website, were still listed as being necessary. I concluded that the site just needs updating and smiled. Good luck.

 

I too have seen the sets already set up for the cross over, no drilling required.