It Done Great , and it don't seem to use as much gas as it did. I run it 3800 rpm @ 45mph for 20 minutes steady, then varied the speed for about ten minutes, I run it full noise several times for about a minute each time, probably 30 minutes all together, and it used about 3 gallons, I can live with that.
I bought another 350 vortec the other day to build up, and I realized that it had the long threaded sparkers in it, and that the heads were fitted for them ... made me wonder, so I made a couple phone calls to realize that All the vortec's had the long threaded plugs. I put the short plugs in my motor, overlooking the long threaded spark plug holes . Duh ?
Today, I pulled the other plugs out, done a compression check, and was pleased about the numbers, 150 to 157 psi with a new compression gauge. I changed the plugs, installed the Bosch plats, thats what the vortec's came with it seems. and after inspecting the color of the sparkers, I changed the jets in the carb, I took out the 72 size jets, and installed some 68's, these are the primary jets, the secondaries are the metering plate, they are 80's.
I'll be taking it out for a run tomorrow morning to see how it performs. I knew the thing has been using Way too much gas, but it ran so good I didn't want to mess with it, but after realizing the sparker thin, I had to make that right, so ... we'll see tomorrow.