The gen 2 coyote and 2mm over gen 1 gen 3 camshafts must be used with the gen 3 chain drive and phasers the exhaust camshaft 1 journal is also larger to accommodate seals which prevent oil leakage from the phaser during operation chain drive. The guys at ford tell us why the second generation coyote engine is better than the first.

Here S What You Need To Know For Your Coyote Swap Project
Coyote gen 2 vs gen 3. Hi all so ive been bouncing around the idea of what power plant and basically it comes down to the three aluminator vs gen 3 coyote vs gen 2 coyote. Torque output also saw an increase going from 400 to 420. 1mm of added lift vs. I know for sure the ffr coupe and roadster will accept a gen 1 and gen 2 coyote. The gen 3 coyote uses gen 2 intake phasers primary chains secondary. Coming in around 1000 more than the previous 2015 17 gen 2 coyote crate engine the gen 3 is worth every penny.
Direct injection with supplemental port injection 121 compression ratio. Power production was again bumped for the gen 3 coyotes. I suppose we may not 100 know about the gen 3 until it. And while the redline remains at 7000 from the factory you can bet with a. Gen 3 cams are still controlled by the same twin independent variable cam timing strategy as the gen 2 versions on the intake side. The exhaust side however utilizes a completely new strategy.
The 435 horsepower400ft lb torque gen 2 coyote motor has been quickly overshadowed by the new 460 horsepower420 ft lbs torque gen 3 motor. The boss coyote engine with 444 hp at 1101 compression at the time this was fords most powerful naturally aspirated engine they ever produced. The revised cast pistons feature a deeper valve relief 3472cc in the first gen vs 4451cc in the second though they do not increase the compression which remains 1101. Horsepower went from 435 in the gen 2 to 460 in the gen 3 at the same 6500 rpm.