I was wrong on using 61 parts ---use the 62 pedals and 62 rod through the firewall and a 62 cross shaft. This is a much better setup -it allows more adjustment (upper rod and lower rod adjustment) plus its a better type in my opinion.. I have raced it and never had any problem.
Do not use the L bracket for the lower rod from a 61 linkage. I used a round rod that is threaded on one end with a pin hole in the other. I will get some pictures.
I think the lower rod was/is close to 10" long. I do have a 409 cross shaft that has one arm about 3/8" longer than a 327 cross shaft. With the adjustment I have the 327 -62 & 63 cross shaft will work fine.
Here is the clutch fork I used (I have a used one like it now) -
http://www.show-cars.com//cgi-bin/commerce.cgi
The original 327/409 clutch fork one is very similar but hard to find and more expensive sometimes A picture of that clutch fork
is in the pictures I posted above of a 62 clutch set. When you compare the two forks the 409 one provides about 1" more throw.
Paul