I think for a bagger that isn't a great setup but then I usually tune for low-midrange grunt. Ask yourself what you want from the bike and then ask people what they would suggest to achieve that rather than deciding what you want to fit in advance. I did a TC88 Road King for a customer and it had the 95 big bore, HSC ported heads V&H Fuelpak and SE 203 cams. It's just gorgeous to ride, effortless and very torquey. If you go with the 510's it will be less relaxing to ride due to the way the cams deliver the power. My pic would be Feuling 525's with headwork and the 95" kit if you want it to haul *** and be easy to ride. Don't get hung up on numbers or trying to innovate. Ask what the 103 heads will give you, probably nothing....with the 95 kit and stock heads the comp goes up without needing a head plane and a good flow job will do the rest. A good blow job will top even that ;-)