We had a customer here that was trying the W8's in Comp, with about 306CI. Six or eight years ago. Spent tens of thousands on dyno time, weeks and weeks. The thing would make 750hp all day long with good spring life at 9500, but that's not going to get it done. Would just break 800 when you put the whip to it, but springs lasted less than 10 pulls. After getting frustrated and beating the head against the wall, did a complete fresh start, started with flowing the heads. They peaked in the 380's from what I recall, and that just wasn't competitive, nor was it what the porter promised. External events occurred and that project was shelved, was kind of a shame. S/F....Ken M