I have TF TW 170 heads on the stock bottom end and stock flat-top pistons. Based on my reading, I’d need a less aggressive cam to improve driveability. I’ve put a little over 1,000 miles on my current setup, and although it runs great above 1,000 RPM, I’m thinking of a change for better driveability.
you should be fine with the N41 but again check your PTV clearance as each engine is different base on variable such as head gasket thickness, have the heads been milled. build tolerances. rocker lift, pushrod length. Very cheap insurance . You should also check pushrod length to ensure proper valvetrain geometry.