Worthwhile easy/cheap head work

[jaik]

I'm taking my car to my friend's garage next week as I think there's a crack in the exhaust manifold (it's definitely blowing and it's definitely up front). It's a known problem on the Cappuccino that cylinder 3 can burn out exhaust valves at high mileage since it tends to run hotter than the other cylinders. I'll be having the engine compression tested to see if there are any problems.

If the test shows up a problem then the head will be coming off to repair/replace whatever needs doing. I was wondering if there is anything worthwhile doing performance-wise whilst the head is off. I don't want to spend bags of cash but any ideas are welcome

The engine's a 660cc 12-valve DOHC 3-pot turbo currently running mid-70s hp (63hp standard) so you know

[chassis 33]

Bulleted bronze guides, may be worth the effort, I don’t know what the flows are like but a bit less metal in the airflow could will help and having them in bronze means the guide is less likely to pick up is something goes wrong and gets very hot, unlike a steel guide.
Regards
Iain