Rob,
I would have responded earlier but I don't remember even worrying about it when I built my car - even odder since I don't have the standard tranny, engine, clutch, or flywheel! - and the last time I hooked up my clutch cable, I didn't pay close attention to how much play there was.
I don't have any specific information for you. I assume you have the correct flywheel, made sure the pin is properly installed in the clutch fork, the clutch release bearing carrier is properly mated to the fork, and clutch return spring is properly installed. The throwout bearing should have the rounded part against the clutch fingers. There is a bushing for the clutch arm cross shaft that if worn would give you more play. It sounds like you have all the correct parts so it should just go together.
There just aren't that many variables so my vote is to put your engine and tranny in the car. I think I can assume you've assembled it correctly (you could break it apart first just to make sure) so if there really is a problem, the only remedy is to reposition the clutch arm which would require cutting it off the cross shaft and rewelding it - or something else similarly drastic - so would proceed as though it's all good because that is the most likely situation. When you get the engine and tranny in, set up your clutch cable first before assembling the rear suspension. Get a friend to turn the engine and another to watch output shafts and test it again. If it still seems wrong and there is something you missed or there is some major problem, taking the tranny out now wouldn't be that big a deal and you can look again. You'd be playing the odds.
That's what I would do but there are smarter people than I who might have a better idea.
