Okay well i tried doing a search for this but really didn't find anything too useful.
I have a GS-R and I plan on turbo charging it soon. My friend is working on a LS/Vtec. He recently purchased a type-r head for his setup. And now he is looking at getting another type-r head for a really low price, and selling the old one. He is also selling his b16a head he purchased earlier.

Now he wants to know i'd I would want to purchase either his b16a or b18c5 head. Now when i did a search i came up with info telling me that adding a itr head to a gsr block would lower my compression ratio a little bit. Which is what I plan on doing with pistons and head gasket as well. Now would it be beneficial to add the itr or b16a head to my car. Would the improved airflow from the head benefit me?

Any input on this would be a big help.

 

The B16 and B18c% head will flow better than your GSR head. If you get or plan to get the ITR intake manifold as well on either head, get it.
The GSR head just does not flow as well as the other two and the GSR intake mani has dual runners for Vtec, which will bring you down as compared to a B!^ or ITR mani. (single shorts).

 

Actually the gsr head flows better due to the angle of the ports, its quench area is smaller so it will produce higher compression ratio as compared to the b16/ITR head.(only by about .2) The b16 and ITR are the same head except the ITR has been slightly ported and has a much better valvetrain. I would use the ITR head with say 9.5:1 pistons and a stock gasket, you would have about a 9.3:1 CR and wouldn't have to worry about you cam timing being screwed up do to a thicker head gasket. I run an ITR head on my b16 with 9:1 JEs and a drag turbo kit and its doing great!

 

I don't have any flow bench numbers on me, but I am pretty definite the GSR head does not flow better than a B16 or ITR head (definitely not ITR, hand port and polish from factory with matched mani I believe).

That is true about the loss of compression points with those heads... about .2

The ITR also has dual valve springs on both intake and exhaust valves as the B16 only has on on set of valves.

 

The port and polish job isn't that extensive, it only extends a couple of inches in from the valve and the manifold is not port-matched. I was somewhat disappointed when I had mine all apart. But it is better than nothing.