[Steve C.]

My previous pump gas 4.210 stroke 462cid street engine dyno tested with a modified Holley Street Dominator intake.

HSD / no carb spacer:
577.9 hp at 5700 rpm, 581.0 ft.lbs. at 4400 rpm.

HSD / 1/2" open spacer:
589.4 hp at 5600/5700 rpm, 589.0 ft.lbs. at 4600 rpm.

HSD/ 1" open spacer:
589.8 hp at 5700 rpm, 590.8 ft.lbs. at 4400 rpm

Here a 11.9 HP increase by adding a 1-inch spacer may not seem like much.
But what about performance on the track, noting Steve25 good info in post 36 above.

.