I have my blacktop zetec engine for the Dax Rush now and decided to install that rather than the DOHC.

It was advertised as a 76k mile engine from a Focus although I have no real way of verifying. I have taken the cam covers off and can't see any signs of wear of the camshafts but I don't know if that is an indication of mileage or not.

Part of me wants to take the head off and do some DIY porting, change the valve stem oil seals before fitting it. The other part of me thinks I would probably make no difference doing a DIY porting and I would be better just putting it in as it is.

I haven't ported a head before and would be going from youtube videos and some handy forum links from fast ford.

Which part of me is more sensible?

Buy a spare head (complete) and play around with that, then you can always swap it on. Plus doing it this way gives you an excuse to build yourself a flow bench

It's a nice thing to do but I wouldn't delay having a driveable vehicle to port the head for what may give you no gains whatsoever, so best to do it on a spare!

I reckon you will be hard pushed obtaining measurable gains through diy head porting on modern engines.

I think this is one of those 'if you have to ask' type questions No is the correct answer! buy a Pinto if you want to achieve something with diy porting otherwise just drop the engine in.

I think the gains would not justify the time and expense. A standard tune Zetec will give loads of power in such a light car.
Its only if you intend to race it that tuning becomes viable.

I say you only live once, GO FOR IT !
Do it on a spare head over the winter if you have to, im sure you could pick one up for peanuts.

What are you hoping to accomplish?
Given that you have never done it before and presumably know nothing at all about the craft.
Moderne engines are tricky to 'improve', armed only with a hammer , chisel , a pair of files and exuberance..

Depends what you want to achieve. Most DIY porters end up with a pile of scrap or a head with bigger ports that flows worse than a standard one because they have no idea what they are doing.

Do you have the kit to measure the port volume, do you have high speed grinders (forget a Deck and Blacker), have you any idea where the oil and water ways are, I could go on but you probably get the idea.

Leave it alone and enjoy.