Bad luck on the blowout mate, that sux big time. Perhaps you should CC the head and plan on a particular comp ratio for your new cam. Remember, cam, carbs and compression = all go hand in hand. I took over 2 mm off mine just to get my cam working sweet. That presented new problems however and I had to get an vernier cam wheel to pick up the slack timing belt. Another story....
Are in the Newcastle area? If you need a hand with anything, I've got the tools and know how with taking off your head. I've built at least 3 of my own pintos in the past and it's not hard at all. Dont pay a mechanic big bux to do it, save the labour costs and buy a cam and then fit it all up at once!!