I have a 07 sg with 103 big bore with stock heads and was thinking about running the 577s, is anyone running this cam and if so is there any good points or bad to this cam.

 

I have always had good luck with Zipper's performance parts. Give them a call and talk with there performance department. I'm sure they can answer all of yourquestions.I have the575's in my Bagger and it performs great.

 

I don't know anything about those cams from experience but from the Big Boyz comparator, it seems like a nasty one! Tons of duration might be an issue with stock heads. I would think those bad boys would have a pretty high power band due to the high lift and long duration. Low end would suffer greatly it would seem. My guess would be that they would smooth out around 3000 rpm's.
Good advice was given to talk to some well known performance guys like Zippers, Big Boyz or Cycle Rama.

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Putgear drive577's in my '06 95" Streetglidealong with ported heads.Love 'em and I'm not saying that justbecause I spent the money. They move the powerband up into the 2000-6000 rpm range. You give up a little bottom end torque but gain so much more where it's needed - who rides at 1500 rpm anyway, that's ping city.The midrange really fattens up and the over rev is outstanding. Most everyone I talked to pushed me towards "low end cams 'cause thats where you need it on a bagger". Ya... Right.My ride still has great bottom end and just keeps pulling all the way to 6000 rpm. Doesn't sign off at 5000 like it used to.It's sweet and frustrates my buddy on his whacked out '07 CVO Ultra (heads,pistons,throttle body) 'cause he can't pull away from me.You may notice a little more rocker noise but not enough to be irritating. GO FOR IT.

 

thanks alot for the great input! I talked to john at zippers and he said this is a great cam for the 103 with flat top pistons and stock heads. I ordered a set and should be here this week i will keep posted on results.