If it was my multipurpose dune/drag bike id go +10 arm, 11 pdl sls extremes with small bore shearer IF's. For gas and alky carbs I like 39 PWK's but really its more important to run what your comfortable tuning. Tuning a motor on alky isn't the scary black magic a lot think it is and it sure does make some power. But for dune riding I can see wanting to run gas and a tank full will take you farther. Just my 2 cents... Happy parts shopping