I don't know if I would call it a mismatched combo. He has a very typical setup. The cams may not be optimized for the airflow that the heads are capable of.
While it is a typical setup, he is still running the stock intake, a cam that probably won't work all that well with the new heads and he could use larger primaries on the longtubes. Not to mention all the other little details about the car we don't know that could probably net more power.
Swap out the intake, cams and longtubes and you may be looking at 20+ more horsepower. Now who would have though 4 years ago anyone would see a stock shortblock 4.6L put down 370+ rwhp NA?
Either way 350+ rwhp is pretty stout for the little 4.6. You gotta hand it to Trick Flow for coming out with a great set of heads.
I myself have dropped all plans of going 4v at this point and am going to do a big bore with the TFS heads. Haven't decided if I want to throw a kenne bell on top or stay NA...seeing as I am using the convertible as my daily driver I may just stay NA and go with the TFS track heat intake and a custom set of cams.
Not to be the Devil's Advocate, but why are the original numbers so low for the combo? That original combo should be in the 320 - 330 RWHP range. The only thing I can come with is that the original setup, the cams were timed retarded a few degrees to ensure PTV contact did not happen.
That said, the gain is impressive. Not impressive enough for me to at this point in time to carry on with a purchase of them though. I was on Modular Depot's list to buy them, but have given that spot up. I am still waiting to see some track results before I reconsider.
To be honest, I think a full N/A Street buld 4.6L( 284 CI ) with the 38CC heads and Flat Top pistons can achieve damn close to if not 400 RWHP on pump fuel. You won't need the bigger displaced engines to get there. A N/A 5.0L Big-Bore race build with these heads will exceed 500 RWHP.
Well my new heads will be here in a few days! Can't wait to see what Fox Lake has done with the heads.......I will post up some pics and the new flow numbers as soon as they reach my doorstep......!
"ED"