ET reduction

Trying to come up with a way to slow my car down.
Going to the Team finals in late October in Dallas.
The car will be running in the 7.0 range 1/8th mile.
I would like to slow this thing down to 7.50 to move it away from the fast cars.
Any thoughts on replacing the 750 Holley with a 500 two barrel on ET reduction?
My thought was that it would retain the 60ft time with the 500 & slow on the back end.
Open for suggestions.