Has anyone installed these before? It looks to me like there should be some sort of spacer with them that bolts on beneath the rockers. Of course, the guy I bought them from (CL) didn't give me the spacers. Contacted YT and apparently there's none in country. Have to order from down under and take 5-6 weeks to get here. Are they a t-shaped spacer or cylindrical? I've found some t-spacers in my stash of bs that may work, but are aluminum. Don't know if they would hold up or not. Any help would be appreciated.
you could make the spacers, can you post some pics of the underside of your rockers? stainless would work ok to make the spacers, of course heat treated steel would be best but since there would be no movement i think stainless could work just fine. You might be able to use them without spacers if you convert from bolt to stud but until i see a pic i can't tell for sure (they would have to be paired on a solid shaft or have a centering pin between them).
you'll get a lot of improvement from the 1.7, the stockers are 1.6 but real life scenario is more between 1.5 and 1.55 as they deform under load.
EDIT: apparently the YT rr are joined by a solid shaft in pairs so you could use studs as long as the fulcrums have a flat side (which would have to go on top) - it might help with setting the preload easier, otherwise you need to get proper lenght pushrods or shim the spacer if needed (although the spacers that come with them should be the proper size to achive the required preload). Harland Sharp has adjustable ones so maybe have a look at those for inspiration.