XU10J4RS head on XU7JP4 block

[lolsteve]

Surely though with bigger camshafts you're allowing more air into the cylinder resulting in a leaner operation due to the lack of additional fuel. Not to mention the messing around with the end of injection and proper fuel atomisation if the valves are opening sooner

It's said by the guy who does alot of the k series mapping that just dropping 135 cams into a 120 engine without the map to correct for the changes results in the engine running dangerously lean top end.