I have a complete 4-speed conversion except the clutch pedal. Does anyone know the value?
The parts I have: 621 bellhousing, Fine spline M20 Muncie 4speed, Hurst Competition plus shifter, Z-bar with linkage, clutch fork, used clutch (I think it's a Hays), Driveshaft with ujoints/yoke, and 168 tooth flywheel.
This was all from a 73 corvette that is being converted to LS1/automatic. All parts in good running condition.

 

when i was doing my conversion on my 78 (auto to 4 speed) i had a variety of "offers" for complete conversion set ups with OEM type parts. here is my experience (and what i actual paid, all with in the last 6-8 months) bought an OEM 4 speed muncie trans for $350 complete with all the linkage and spent $150 in parts to completely rebuild it. the clutch (used) in my opinion isn't worth much as anyone making the conversion will probably want to go with new stuff. i bought a centerforce II set up (complete) locally for about $300. i bought a 621 bell housing in perfect condition for $175 shipped to my door. a good pedal assembly was a bit harder to find, but i was offered a rebuilt set up completely refinished complete with the clutch lock out and the brake switch for $150.00 (you can get them cheaper by a lot if you want to refinish them yourself). all the other parts like the Z bar, fork, ball pivot, various rods brackets and boots, etc totaled well under $200.00. i had a brand new drive shaft made for $100 locally to insure it was balanced, etc ( used ones go for under $50 and then you need to insure they are ok, etc) and i had to buy a 4 speed starter ($150) which i also got locally. a good shifter mechanism can be had used for under $150. i bought the mechanism, had the linkage from the trans, found an NOS stick shaft and bought new repro ****, t handle etc and it cost less than $200.00

i hope that gives you some kind of ideas as to what your stuff might be worth.