Kazoom wrote:no, the "3V" aussie Copy exh port must be compared to the old SVO head as the old iron 2V head exh port height is no higher than the iron 4V, the aussie "3V" copy and A3-b-c are much closer to each other.
The A3 hadn't been invented, so how can it be called a hi-port if it wasn't higher than the iron heads. 3V 90mm, iron head 90mm, not much difference.
It looks like SVO made an alum copy of the modified 4V, but changed the ports and made them better - an evolution, which is the same as a 3V. Looks like the SVO is a copy too.
I think your picture say it all, because those ports don't look like each other at all. Get some port molding compound, and it will open up your world.
Kazoom wrote:also the 4V cc Hi-port mod was done by Every American P/S racer that was serious about winning as FORD them selfs stated it was good/dynoed for a MINIMUM of 20+HP (heard some getting over 30+HP), 4V cc was the TOP DOG p/s cleveland head so mod is more than a small gain, NONE of them were waisting time or money with the inferior 2V head.
20 hp on a 900hp engine, so what should I expect on a pump gas street engine, maybe 10hp - told you it wasn't much -.
Pump gas 4V intake filled no hi-port exh, we get 601hp
Pump gas 2V ported only, we get 585hp.
If you do the development, the 2V isn't that bad and requires less mods.
Kazoom wrote:the Hi-port mod may not be for every build but it is still a great mod for some guys that want to take there old iron 4V heads to the next level.
The guy is a street guy, so if he did the mod it would be more for show than go, because it's a lot of work for only a small gain.