hmm... toughy....
A frankenstein build can rev to 8 just fine, but most people use a block guard to keep the main bearings in check. Without something stiffening the lower end, I'd be hesitant to run it much over 7k RPM, which doesn't give you much VTEC time.
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-Harry
AIM: NDcissive
CRX and Pre '92 Civic, Engine Tech and Tuning, & Track and Autocross Forum Mod