DEFINITLY re-surface your flywheel, but make sure the shop that does it let's you know how many Thousanth's they took off, sometime's if you take material off and don't use a flywheel shim between the flywheel and crankshaft you'll have trouble maintaining and/or getting the proper clutch adjustment.
You can buy those shim's in assorted thickness's
Actually, most good parts store's like NAPA sell new clutch's and can only get re-manned one's if you ask for em'
The 400 flywheel you have will accept either a 11" or a 12" clutch, and other then the flywheel balancing itself everything else about your clutch setup will be the same as any Chevy 350/305/283/ Big block(i think) /etc....
I just put a new NAPA clutch in my 74' K20 and i've been very happy with it. Which suprised me because i almost bought a Centerforce since i had such bad experiance's with the diaphragm style clutch's i had run in the past.
Just make sure you get the 3 Finger lever style clutch,
because, as the guy at the store assured me;
they are stronger, hold better and so far have taken the abuse of my Stock 350ci against 37' rubber with a very heavy throttle foot and a belief in using the highest gear the engine will pull for max. wheel speed.
The drawback of the lever clutch is that it WILL have a heavier clutch pedal then the diapraghm style ( but it's not real bad, we're not talking Mack truck heavy here),
If you absolutly want the softest clutch pedal effort you can get, you need to go with at least The Centerforce serie's of diaphragm clutchs, all the stock style diaphragm clutch's i have used have all sucked in Offroad situation's.
If your interested in the NAPA clutch i used, i just found the part# in my record's
It's Line code is:
NNC
& part#:
MU1862-1
This set will include a;
Clutch disc, pressure plate, throwout bearing, pilot bushing (and a pilot bearing i believe you will just throw away since it's for the newer 1 pc main seal engine's) and a plastic clutch centering tool
all that should cost less then 150 dollar's for the whole set
Good luck man /forums/images/graemlins/thumb.gif