I"m currently working on a "sleeper" spyder. I'm using a classic spyder and I'm going to try and make it fireable at the lowest pressure possible. Originally that wasn't the plan...but it seems all the aftermarket parts for these guns are made for LP operation. I'm currently waiting on a pile of parts to come in, this LPC just happens to be one of them:
hehehe
I'm probably going to be doing one of those updated regularly updated project threads soon enough.
I do have a suggestion though. I made a pump spyder a few years ago. It order to make a new valve pin that would eliminate blowback I had to rig up a "lathe." I took a corded drill and put it in a vise, upside down. Turn it on and you have yourself a rotating rod for a perfectly symmetrical valve pin. I put the cut to length rod in the drill. Then I used a dremel grinding wheel to get it roughly down to specs. After that I used sandpaper to smooth out and finish it up. It worked great, nearly eliminated all blow back
Anyways, you could use the same process to make yourself a new high flow valve pin.