Makes a big difference in price, LOL Ive seen the 72 from $80 to $150. The 70-71 are stupid money, Ive seen those as high as $350 and the 68-69s Ive seen $100 to $200
also 72, 73 and 74 all use different air cleaners. 72 has the flapper, 73 doesnt and 74 has no flapper and a round snorkel...