TV boost valves- o-ringed vs. non-o-ringed

[Longroof79]

As I'm trying to figure out the parts needed for my 200-4R build, I noticed that there's two types of boost valves used...o-ringed and non-o-ringed. That also applies to the low/reverse valve as well.
What is the advantage, or disadvantage of using one or the other?
I'm guessing the o-ring type allows less pressure loss?

 

[motorheadmike]

If the valves were an interference fit you could go with the non-o-ring valves. But, wear and manufacturing tolerances indicate the need for a way to reduce pressure losses.

 

[Longroof79]

Mike,
I am assuming that the o-ring type might be for pumps that have had significant miles and wear.
The o-ringed valves might help compensate for bore wear....again, I'm speculating.
Anyone else have a theory on this? What do some of you transmission builders suggest?

I found an explanation on the Sonnax site. It explains the purpose and function of the o-ringed valve.
https://www.sonnax.com/tech_resourc...imize-performance-with-sonnax-o-ringed-valves

Thanks again Mike. You pretty much explained it. No one else seems to have an answer for me...oh well.