2G head vs. 1G head?

[Groomz]

From searching I know that the 1G head flows more from the factory than a 2G head. My question is it worth it to go for a 1G head w/ a full port & polish vs. getting the same amount of work done to a 2G head? I am shooting for 400+hp. It will be a street car for the most part, w/ little if no drag racing. Is there any machine work necessary for a 2G head to fit a 6 bolt motor? Thanks for any info!

 

[allwheelTSI]

if you're going for 400hp,the stock 1g head will do you just fine. a little polish and removing of the casting marks would'nt hurt.

 

[13secGST]

I have often wondered the same thing...but I think I read on a place that builds performance heads, that the way the ports in the 2g and 1g heads are different...its not just that the 1g is bigger, it has a slightly different path...so if your shooting for 400, then you might as well go 1g cause its not really gonna be much more..

 

[dave99gst]

ive always heard that a port+polished 2g head is better than a p+p 1g head. stock for stock.. 1g will give ya more top end.

 

[Groomz]

Lets say I get a race ported and polished 2G head with Crower springs and titanium retainers. Same price for a 1G or 2G head, does it really matter? I've searched and read that most power gains from porting and polishing a cylinder head come from fixing manufacturer mistakes/imperfections. So a well ported and matched 2G should be good for some extra power. I do know that the 2G heads have better cooling passages than 1G heads, but I don't know if that means anything in the long run.