I have a set of C.O.M.E heads, not sure what series they are (as I purchased them from a race engine, the engine was in a Torana for 2 seasons only). Same valve sizes as your looking at.
I think that they are very well manufactured and I am happy to recommend them. You will have to run stud mount roller rockers, hardened pushrods (you need to change length anyway) and guide plates, but they are all worthwhile upgrades as well. Just keep in mind the extra expense that they will bring.
I have measured and photographed mine a month or so ago before they went on the stroker engine. I noticed a quirk or two and wonder what they discovered with all there R&D before releasing them for sale. I just get the feeling that someone knows a lot about fluid dynamics in there design of these.
too sum it up: there are cheaper ways to make power, but I feel that these heads make extra power with no loss or downside (unlike a cam that will sacrifice one rpm range for another)
If you already have good stroke, good compression, cam, intake etc, etc. Then this is the next logical step and definitely worth looking into.
It would be interesting to compare the price of these against modification of standard heads to similar spec (valves, ports, pedestal's etc)
they are also lighter and transfer heat faster.
the only downsides would be:
- more risk of damage if you happen to overheat your engine
- longer cool down between running an engine and removing a head
But these should never become issue's