feedback on 8" boosters

[Pont406]

Thinking of buying a smaller booster to get more room and maybe it will help with low vacuum. Something similar to this one http://www.ebay.com/itm/221036147208...84.m1423.l2649
Did any one try one yet? How is a feedback on them? I already have power brakes but can't find a small booster by itself . I want to get some runs at Irwindale 1/8 mile and theirs shut down area design mostlly for newer vehicles. Even at 80mps somtimes it's a bicth to get off. It will be a little faster now. Thanks a lot