If you just want to drop the output voltage of a 7.2V 6-cell pack down to around 6V, why not just wire up a 1A diode inline with the battery pack? Any of the 1N4001, 4002, etc. will have a forward voltage drop of about 1.0V. Twist 2 of them in parallel to get 2A capacity if you're really worried about current draw with that hot-rod gasser of yours that can spool up to 15,000rpm.

Really though, why carry the weight of a 6cell pack when you don't need it? Remove 1-cell and be happy. A while back, I bought a whole bunch of Nokia cell phone battery packs from www.allelectronics.com that are 6cell NiMH 850mAh. I break out the cells, which are rectangular and look like bricks, and make RC packs out of them. Work great.

Voltage regulators have their uses obviously, but I don't buy all that hoopla about expensive LiPo packs and shiny regulator heatsinks. People buy 'em because they look sexy inside a 40% Yak and because the Pros use them. For me, direct cconnections and heavy-duty switch/connector is the best policy.