I've had virtually the same heat shield on a TBI header car for the past decade with no issues whatsoever. Jessie Buhr now owns the car. The downpipe gets close to the rack and pinion on the TBI header, but the #1 exhaust runner is very close to the pump. Probably closer than the Masi application. Had Thermo-Tec wrap on a small area on the downpipe that was most critical on the TBI header. Also am going to use Aeroquip Fire-sleeve material on the pressure and return lines. Not worried about it at all. Just posted pics so OP could see it fits with large plenum style intakes. Bottom line is I know it fits, works, and lives, just fine.
Quack's Masi GLHS I put together what 12+years ago also had a ZF pump on it with no ill effects. That wasn't hardly a stock masi powerplant.
Todd