You mentioned that you had an adjustable cable before right??
therefore, I have to assume, and I think I'm correct that you have an aluminum quadrant under the dash right??
installing a non adjustable cable onto an aftermarket aluminum quadrant with no firewall adjuster will not work right. It's almost gauranteed to be way, way too loose. You can try it, but it won't work right, you'll know instantly, you'll have almost no clutch pedal because there is nothing to tighten the slack out.
go to upr.com, order their extreme firewall adjuster and have them rush it to you, unless you can find a local place to get it.
also, be sure your cable routing is correct, if it isn't that's a surefire way to snap cables.
my engine compartment looks like ass. i've let the car sit for the last 6 months while I restored my entire interior. here is how the cable should be routed