More numbers. Initial CARB tune was far too rich, only 177 on our dyno but AFRs well under 10, while the car was still on the dyno same day Mat cleaned that all the way up to 204 hp in about an hour of work. Thereafter Edelbrock leaned the CARB tune to nice AFR range of 11 but we have not redone the dyno run with stock header on our dyno (on the Mustang dyno at Edelbrock we were right at 190 HP with stock header and leaner CARB tune). With that same leaner CARB tune and our shorty header we were 197.8 on our Dyno. As noted above OVT Mat's tune for stock header was 204 HP on our dyno, and with this RoadsterSport shorty header Mat's result pushed to 214/217 range...so custom tune adds roughly 10 hp, the header adds roughly 10hp. My wife didn't like Mat's tune, not finished enough in part throttle smoothness, she loves the CARB tune and doesn't miss the comparatively small hp difference. Thus, the 'wife approved' choice currently is the CARB tune...and this is what it looks like with header. Mat is still working on his tune, Edelbrock had over 100 hours in their work so the comparison is not fair at this time and I expect this may all shift in time.
In sum, got some dealers saying this kit added 70 hp.....which seems high based on our experience so far on two different dynos. Our results are right about 50 hp, give or take depending on CARB tune or custom, stock or aftermarket header, etc. Stock post break-in hp on our original two ND was about 140 hp on our dyno, but this car tested stronger in stock form, 148 was best totally stock (best of any stock ND we tested). Thus, we are up an even 50 right now....and it's awesome. Any more and my wife might be intimidated by the change, with the current results we are often fighting for who gets to keys for the fun of driving it.