[LMH]

I'm sure Bob can tell you more specifics as they apply to ERA's but CSX2345 for example, didn't use a top loader, rather a BW T-10. The shifter position for small block cars puts the shifter 16" back from the bellhousing, center line of the shifter in neutral. That may help you determine what housing or position is needed.
ERA might be different though depending on engine placement and interior aluminum.

Larry