You can buy the 351W stud kit and don't have to use a spacer.  The kit is available from Summit. The 289 windage tray is a Canton CTR-20-930.  There are several SBF windage trays that do not work with the Y.  The best one is in the picture below.   Joe-JDC

JDC

Hello Members    Was able to find main bearing bolts with studs to mount a Canton tray on a Y-block. Arp has them was quoted 25 each plus shipping. Jegs has them also, very hard to find, but at 20.49 each better price with free ship if you buy enough other stuff. Jegs # 070-HARJ3.500-1   You will need a spacer under bolt head like  Ted E described in his post about how he went about mounting tray on Y-block. I found that a 7/16" thick spacer will work for me.  I used a 1/2 inch line shaft collar (is 7/16'" thick and got at hardware store) and filled set screw holes .  Ford does not service this bolt anymore.  Funny thing, can buy 100 for 415.00. Wish John M or somebody that sells Y-B parts had them. Bill  Oregon