CVOjunkie,
Have had Head Quarters work their magic on 2 sets of Evo heads and 3 sets of stock Twincam heads over the last several years. Put an Andrews EV27 in one Evo, and Andrews TW37G's in one 95" Twincam for low-end grunt. Neither combination made peak numbers to brag about, but torque was quite strong down low where I like it. The other two 95" Twincams had S/E 21 tooth engine sprockets installed, so went with HQ TC-575's in one and HQ-0033's in the other.
103's have their own unique cylinder head castings. You may want to call Head Quarters and ask what their thoughts are regarding working with 103 castings. Doug Coffey is very knowledgeable and I've been pleasantly surprised how much time he has willingly spent with me discussing combinations. Unfortunately this is teardown season, so they are probably quite busy. Head Quarters does have an exchange program, but I prefer to get back the heads I sent in.
There is an area on Head Quarters' web site where you can view dyno sheets of customer's bikes. You can see how much a given combination will yield and where in the RPM range. I actually printed out all of the Twincam dyno sheets, and spent some time reviewing them before deciding on the last combination. I even requested they size the combustion chambers to yield a compression ratio of my specification.
A co-worker sent his stock Twincam heads to a guy in Michigan, and I have seen what he can do with the 103 castings. If you're intersested I can send you some info on this guy.