I consider the Moroso slide rule to be the default "target" for performance....... IF the dyno numbers aren't BS.

A really well sorted out car can surpass the Moroso slide rule, but most won't.

From my experiences, if you have pretty accurate engine dyno data, you should be able get the hp number on the Moroso slide rule to come within about 5-7% of your corrected hp, based on speed. This assumes you're not running at altitude adjusted tracks.

For example, if you have a 500hp motor(std corrected hp), and put it in a 3600lb race weight car, you should be able to get it to go between 119(465hp) and 121.8(500hp)mph.

If after trying to get the combo sorted out it still won't go at least the 119, and you're not running at an altitude track, you have to start considering the dyno numbers might be a little optimistic.