After spending most of the weekend in the Manley, Supertech, Ferrea, Crower, Crane, Comp Cams, Crow, and Performance Springs catalogs and specifications, I developed a short list of 6-7 spring sets that should work with these RB26 retainers and our engines.
Then this morning, I called the two US companies that made the short list to confirm their spring specs and order samples. Both Oz companies made the short list too, and hopefully a mate there will handle getting those for me.
Interestingly, both Manley and Supertech confirmed that the RB26 retainer is the only commonly available retainer which:
1) Will work well with 31mm lifters, and
2) 6.00mm valve stems, and
3) Has a shim recess for shim under bucket setups, and
4) Standard size shims are readily available
Supertech said they do make a retainer for the JDM Subaru WRX motor, that would work OK, but the shims are an oddball size of 11.70mm, and are only available from Japan......
I should have samples of Manley's and Supertech's springs by Thursday, and hopefully those from Oz the week after, so we'll be doing some detailed spring, shim, and retainer testing soon.
Stay tuned........