Use a clutch fork from a mechanical style release mechanism and then use an external slave cylinder. You want your clutch slave to have a bigger bore than your clutch master cylinder. If you use a 0.875" bore master cylinder then you should use a 1.00' or 1.06" bore slave cylinder. GM used both on their C-10 delivery vans and they are very low cost, readily available over the counter Dorman parts. Look to someone like Wilwood for the clutch master cylinder.
Here is a link to a bunch of slave cylinder pics =>
Slave Cylinder Pics Pick one you like and then build a bracket that bolts to the clutch can mounting bolts to secure it. Here are a few mounting bracket pics (mixed in with a bunch of slaves) to help visualize various alternatives that might work for you.
Slave Cylinder Brackets
Here is a link to an Iconic slave kit for a Coyote / Modmotor.
Iconic Slave Kit
The Iconic kit will not work for an FE but it can give you some ideas. The FE style would mount to the bellhousing (can) flange and push the fork back towards the rear of the car. BTW that is a C-10 GM delivery van slave cylinder.
Ed