308 heads

[immortality]

whats the best heads for a 308, haven't decided yet if i'm going to stay pre efi or use the later efi style heads as they don't have siamesed exhaust ports(and the hot spot that would go with that). i'm currently running a 4bbl TB injection setup with brocky 'B' cast heads.

cheers

Bart.

p.s. do you have flow figures for these heads etc

[Blown V6 Hatch]

For a pre-efi 308, you cant go past the dash 3 alloy heads, but thats if you have the dollars to go alloys! For efi, the VN efi heads are pretty good from the factory with some good port work, or if you have the dollars go with the dash 9 alloys!

[TappetHead]

The EFI heads have a higher port angle so they flow better with the same size port cross section. Don't compare port cc's though, cos they are a much shorter runner than the carb version.
A lot of people are staying with the early model heads these days and getting good numbers out of them with the Torque Power range of manifolds.

[AirStrike]

Keep in mind if you change to EFI you also need to change the cam to suit along with having injector bosses drilled in the manifold.

[immortality]

Originally Posted by AirStrike

Keep in mind if you change to EFI you also need to change the cam to suit along with having injector bosses drilled in the manifold.

i'm already running EFI through a throttle body injection setup so it's not difficult to change over, when i decide which heads i'll use then i'll get a cam to suit. i was considering keeping the 'B' cast heads now as it's a brocky modified commodore and i'd rather keep it reasonably stock, maybe a good port and polish to start with, solid cam, scat rods, forged pistons, original crank cryogenicly treated so it can pull decent revs etc i know i should be able to get 400hp with these heads with original stroke etc, then i've got a BIG NOS kit to go on top of that so 700hp total with nos is the target

[Blown V6 Hatch]

Originally Posted by immortality

i'm already running EFI through a throttle body injection setup so it's not difficult to change over, when i decide which heads i'll use then i'll get a cam to suit. i was considering keeping the 'B' cast heads now as it's a brocky modified commodore and i'd rather keep it reasonably stock, maybe a good port and polish to start with, solid cam, scat rods, forged pistons, original crank cryogenicly treated so it can pull decent revs etc i know i should be able to get 400hp with these heads with original stroke etc, then i've got a BIG NOS kit to go on top of that so 700hp total with nos is the target

Reasonably stock???? If you do all that to the motor all that is left of the Brock engine is block heads & crank. Please tell me you are not doing this to an original Brock engine?!?!

[immortality]

Originally Posted by Blown V6 Hatch

Reasonably stock???? If you do all that to the motor all that is left of the Brock engine is block heads & crank. Please tell me you are not doing this to an original Brock engine?!?!

unfortunalty it's not one of the 500 he built each year for homoligation purposes, if it was then i wouldn't do that much with it. it's an HDT modified commodore, someone purchased it as an SLE and then HDT modified it. i'll keep the original rods/pistons so i can always revert it back to original.