[blykins]

Did you try another cam?

The good sbf heads are not lacking on the exhaust side, unless you're making up for forced induction or nitrous.

I've never used more than an 8 deg split, even on drag race and road race FEs....that are supposed to be "exhaust compromised"...

What happens with a street engine is that you end up with a great deal of overlap.

I would rather match the lift to where the heads work the best then cut the split down to make it more streetable.