Richard,
I have looked through my rosters and don't find anyone that I have shown as being at Pleasant Hill or in one of the units you mentioned. I have one guy from Co. C that was at Port Hudson but that is a different story. I have, whenever possible, included men that joined other CS units but don't find any that would have been at Pleasant Hill. However, it is very possible that more than one out of over a thousand slipped through. Usually, men that were discharged, I gave up on unless the same exact name appeared in Booth's. Other than that, all of my info came from the CSR's and other places. Here are two men that served in the 8th but I don't know if either of these units were at Pleasant Hill:
Robert P. O'Bryan - Spaight's Texas Cavalry
D. H. Quirk - 2nd La. Cavalry
Let me know.
Thanks,
Wayne