Alright i think its time to do some more tuning on the ol 1406 and i figured id ask and see what some ppl sugest as to what rods/jets/springs to throw in. As of now its at stock specs when i got it it had .100 jets for secondarys but i changed them back to stock. The car runs and drives great until i get in the upper rpm and it feels like its leaning out!? Motor is 305 bored 030 shaved 416 heads screw in studs z28 springs summit 1103 cam 1.6rr performer rpm intake and long tubes. I have light springs in the dizzy with all new dizZy plugs and wires. It seems to cut out around 5700-6200rpm like its missing or a rev limiter. It pulls hard and feels like i need to shift at 6200 but like i said it starts cutting out sooner but it always varys a few hundred rpm sometimes its fine till 6. if i free rev it will go to the moon just when under load it does this.it likes to backfire when i let off from a wot run sometimes too or pop and crackle.

 

Sounds like you may just be running out of camshaft. That one (per the Summit site) is all done at 4500 revs.

 

Well it pulls hard all the way up and just acts like it hit a rev limiter! Im gona go back through and recheck plugs wires timing carb setup when i build a new trans xmember and true duals with weekend

 

That's a misprint. With 272 degrees advertised duration, it's good for more like 5700-5800.

But, you're still reving it way too high. You aren't leaning out, you're floating the valves. Better springs might help you to get more RPMs, but 6200 is probably stretching it.