Hello. I have a GSC S1 Intake cam, and Cosworth M2 Exhaust Cam. They both have 11mm lift at 1mm, however M2 has more duration. I was wondering if anyone has any idea what will happen if I drop this combo in? What happens when the intake cam has less duration than exhaust cam? Any suggestions would be appreciated. Thank you.

Nothing happens--that doesn't happen with any cam combo. Lots of split duration combo on the market. I ran 272/264 myself. and now run 274/278. You usually run the longer duration on the side with the most port restriction. ( I digress). You will be fine, you will still be limited to the rpm of the intake in relation to power band, in this case you should have a great low end and midrange combo. good luck