called a side cover, less commonly a pushrod cover - the cover itself would likely have to be found used, but gasket available, maybe even at your local parts store

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot