'04-'06 1200 Sportster heads

I have a 2005 1200R sportster and I hve Rejetted the Carb, V-Twin Pipes, Hypercharger,and N3 andrews cams,Why can't I put larger cams in this engine? all the ads say I have to do Head work...what kind of work do I need to do? surely it is not just spring & retainers Because you would think the manufactures would put that in the ad

Should Be Able To Put A Bigger Cam In Without The Head Work, The Only Reason I Would Think You Need Head Work Is If You Put In Bigger Pistons. Cam Should Drop Right In And The Adjustment Sould Be In The Pushrods. From Experence They Tell You Things In The Adds And Half The Time They Are Wrong On What You Have To Use Or Do. For Example I Bought A New Bat Box For My Rigid Frame, Because They Said To, The Old One Works Better, Said I Needed A Aftermarket Rear Brake, Old One Fit On Just Fine. If Your Looking For The Power, J&p Sells A Hop-up Kit All The Way Up To 100ci For That Motor.

Depends on the cam. Some applications require stiffer springs, cause the stock springs may not be able the handle the longer duration of the new cam. Of that depends on the type of cam you get. Best of Luck!!!