[Kurt in NJ]

If you can put a couple of drops of oil on the face of the bearing/finger tips of pressure plate and the noise goes away there is a alignment problem with the snout of transmission and the crankshaft centerline making the fingers scrub in-out on the face of the bearing, a little oil will stop it for a while
I worked on a car that had the clutch out over 10 times at 4 different shops, ---what I noticed was alot of wear on the contact surfaces of the fingers and the face of the bearing---a lot of wear for something that had so many new parts so many times---the bellhousing dowell pins were missing

you have a modified engine to non original transmission---how was it centered to the crankshaft centerline, perhaps there is a centering ring/adapter that is out of place or missing----or something went wrong on the alignment of the adapter plate
if you have a dial indicator indicate the crankshaft to the part of bellhousing that aligns transmission if possible