For key word rankings, my sites wipe out the competition on Yahoo but I am only on par for Google searches. What would be the key differences for my sites higher rankings on Yahoo?
May be your site has more links in Yahoo than in Google. Build links from pages that are cached by Google and you'll get higher rankings.
Yahoo places more importance on onpage factors and Google on offpage. Without knowing your site, as a guess your keyword densities are probably slightly high and you have too few quality links.
I think that you should always concentrate on ranking higher on Google. it is easier to rank in Yahoo, but it does not provide that much results in traffic for your website. You off- page SEO (linking) is very important to Google, try to do get some more links to your site from high PR sites. My advice would be do some social netwoorking(digg, stumbleupon, hubpages, squidoo etc.)
Laurux7 correct. On page seo important for yahoo, but off page seo important for google. this about that both if you want good ranking.
The google ranking has got more competition and everybody wants to work on google SERP That is the reason for difference between google and yahoo SERP
the difference is as abvious as the moon, google is the bigest search engine on earth this creates competition beetween people who are seeking to get listed as quickly as you do.
I suggest you to do a well-balanced SEO (on-page and off-page).. for an improvement in rankings on both SEs as well as the other not-so-popular-than-them SEs