I'm going to attempt to bolt the trans with the 340 engine today. I have 2 pressure plates that came with my project and not sure which I should use.

Pressure Plate #1) Is a rebuilt unit (I think raybestos) with 3 fingers and is fairly heavy.

Pressure Plate #2) Is an older brand that is supposed to be performance. It is a Ztreeter brand and has lots of cone shaped fins as opposed to the 3 fingers. It is lighter.

Which should I go with?

The three finger one is probably a Borg & Beck type [ could be a Long type ] and was the type used by the factory. The one with many smaller fingers is a diaphragm type. The Borg & Beck will very likely make for a stiffer pedal and will require that you keep the pedal overcenter spring in place in order to keep the pedal effort reasonable. Borg & Beck type clutches tend to be very reliable which is why the factory used them. Diaphragm clutches give a lighter pedal feel and can work quite well IF they are well designed. Centerforce,McLeod, and Sachs all make good diaphragm clutches. I don't know anything about the Ztreeter clutch. Improperly designed diaphragm clutches lack holding power and tend to hang up at high rpm. Some people remove the overcenter spring when using a diaphragm clutch, but this isn't necessary if you install a positive stop on the clutch pedal to prevent overcentering. The choice is yours.

Ztreeter Clutches & Zoom Gears = Same Company

I remember having a Zoom clutch in my '66 Street Hemi. Not very impressive, at least not in a good way. Maybe they're better now.

Thanks for the input guys. The Zstreeter had been sitting on a shelf for 20 years and I couldn't recall the actual quality of them. After I read your posts, I went back and looked at the Zstreeter unit. The edges of the surface area were pretty rough and I could actually flick pieces of metal off with my finger nail. After looking at both units again, I went with the Raybestos one. It just looked better made overall.

Thanks again for the advice.

Good choice. Over the years I installed two Zoom clutches in hod rods. Both failed in short order.