funny that but true the 4 port is the choice for even the similar RB engines for a good reason. The 8 ports have more low end turbulence which only is good with the extra butterfly setup and for NA only. For boost 4 ports all the way.

http://www.lewisengines.com.au/category25_1.htm
1200aud for ported 8 port might as well go 4 ports right up

Hi guys im going to make a custom gasket,what thickness should i be looking at.Im going to get a stock 8 port gasket,draw it onto the gasket paper then do the mods then cut it out.If i get a mtr then i will have plenty if i mess it up.So what thickness 3mm.

Ive got a 4 port head in brisbane if anyone is interested.

Thanks mate,what thickness should i be looking at

Supercheap, Repco, Autobarn. Any auto parts supplier has rolls of gasket paper in different thicknesses.

Hi Oda where do i get that from?

just buy some new gasket 1mx1metre and cut your own gasket to size

Hi guys this is what im planning to get done convert the 8 port into 4 port but am worried that the gasket is going to get in the road and restrict flow.The gasket will be slightly moded.Anyway this is the head after being converted.Im begining to think that a standard 4 port head will be better as i have the opertunity to buy one.

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With a redline of say 8K for a worked motor, and a turbo that spools at say 3k, you're going to be using that extra bottom end that the eight port head gives in 1st gear only. In a hard launch you'd be above 2k anyway, so I say four port all the way!
(Only because I have one of course! hahaha)

Yes, 4 ports are better for full-throttle, high RPM use. Makes a bit more top-end power.

But the 8 port manifolds actually make a lot more torque below 2000 RPM (about 1/3 more power), and are very close to the same top-end power.