Quote: [ Some people here think their -1 heads flow 380 or more.
some people on here do have -1's that go 380 or more.....................
My flow sheet says MORE than 380 on a 4.375 bore/fixture...
Most good porters can get 375 to 380 cfm out of them, with a 2.25 intake. Mine flow 399/400 at huge lift due to using a 2.30 intake valve (.800/.900) but with the cam and port remaining the same the car never went faster. The flow with the bigger intake valve also had a weak spot where the flow at about .300 stayed exactly the same, so that might have been part of the reason the car never liked the change.
