Nice plan for becoming engine, except in one thing. I guess you propably are saving money in wrong point.. I mean the valve springs. In company called RallyRace (guess you know the place already?) there are stiffer springs and they cost about 79 euros.

After all you were talking about 7000rpm.

And yes I got stock valve springs in my pinto too, but itīs with original ECU/ignition, so the rev limiter is somewhere near 6000