I just installed a rebuilt GS350 I added the comp cams 268h cam with 268 degree duration, 469 lift, as well as lifters, springs timing chain gears etc, its been bored 30 over with TRW pistons and stage 1 intake. No other mods were made to the heads except the springs. added msd coil and module. It will run very nice as long as I hold it to 1000-1200 rpm but as soon as I let off the throttle it dies immediately no hesitation. I plugged the vac lines still no change as well as rotate the dist. Any suggestions on how I can get it to stay running? Anyone's help will be greatly appreciated.