Need advice for slowing my car down consistently.

I normally run in Pro, but this year I’m going to run Sportsman. The “short” reason is, I only race with the money that I save over the winter, and this year (thanks to breaking my rear end last year) funds are in short supply. I could either race part of the season in Pro, or the pretty much the whole season in Sportsman. The bottom dial for the Sportsman class is 12.0, but my car is capable of running 10.7’s….So, my question is, has anyone slowed their car by over a second with good results (consistent, round after round)?

I was thinking of either adjusting my throttle cable so I only get about half throttle and trying it, or putting a block under the gas pedal. Has anyone tried either of these, and did you have success with it?

Another option I was considering was putting an adjustable dead stop on the carb that could be removed remotely using an old choke cable. So, for example, if I was running down the car next to me and needed my whole gas pedal (a little extra power to take the stripe) I could just “remove” the dead stop with the pull of the choke cable. I don’t think this would be considered cheating, but what do you think? The class rules say a dead stop is legal, and everybody and their brother has a nitrous system on their car for “just in case I need it”, so I think it would be OK in comparison…but I don’t know.