I was considering getting my trailblazer ported and I was wondering if it makes a noticable difference. I was thinking of getting maybe a stage 3.

 

You could ask on the Polaris forum for an answer to your specific heads...

I just did them my on my Prairie, when I was installing my 750 cc FST kit... I talked to 3 different flow bench techs, & the general consensis was that I'd see about a 20% improvement.... while I think they were pretty optimistic saying 20%, I'd say that I did notice a big improvement...

heads are all cast differently, & there will be different gains to be had from brand to brand, model to model, sometimes year to year... the best bet would be to take your head to a compitant tech & see what they think...