p,
Lift and timing are not a problem. The lobe width on the two is different. The lifters are different. As you already know, the oil pump drive is different. I'm not certain, so look further, but you could wind up with rocker geometry problems as well. Have you got Vizard's book?
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon