A 604ev installed into a ZIF carrier would work, but only in a system with a Kansas ROM (meaning you'd be replacing one 604ev with another).

The backside cache is on the Apple 604ev card (1 meg of L2 at 100 MHz). While G3 and G4 ZIF cards almost always have L2 cache, the 604ev ZIF doesn't. You get the dual 32k L1 data and instruction caches, and that's all.