Hi, I think I already know the answer to this, but I just wanted others' opinions .. can the cams from an ST170 fit a standard blacktop head?

Don't know for sure but I suspect not as the st170 have to work with the vct variable valve actuator.

Yeah, I suspect that because the ST170 inlet cam has a thicker 'neck' at the belt end to work the vvt, it won't fit the blacktop. There's mixed responses on some other forums which have thrown me..

No they won't, head is machined differently on the pulley end of the inlet cam. I have heard rumours the st170 head fits on the blacktop bottom end. Though why you would want to do that is beyond me as the 170 bottom end is better anyway. Full engines can be bought relatively cheaply.

Spill the Beans Rab, what you up to

ST170 cam is a better profile than the black top. But as said it doesn't fit due to the pulley end bearing size being much bigger on the inlet.
The exhaust cam may go in. But the lobes are wider than the blacktop and the followers are bigger. These will swap over but they will need to be shimmed.

ST170 head will go on a blacktop block but the piston to valve clearance would need to be sorted. ST170 pistons are notched and the rod ratio is different too.