The cheaper head gaskets are the standard head gaskets and the ones that you will need to use. The other head gaskets are thicker and will lower the compression.
I was thinking both explanations, but was leaning towards thickness.
Thanks
I bought a couple low mileage 24k, GW GL1500, heads to port and polish. I tell u what, the exhaust ports for Cylinders #1 and #6 below the valve are really, really bad due to the hole for the EPA PAIR valves. The hole just sticks out into the exhaust flow like a scoop. This can only be seen after the valves are removed. the other ones need to be cleaned up also, just not as bad. A good port and polish of the exhaust should easily see a 10 HP increase, plus a nice MPG increase.
The intake ports don't look to bad.
If I can't find somebody good in my area, I will try porting them myself.