V8 u can find them for 400 for everthing on e-bay r look on ls1tech they r on their all the time

 

I think you need a new cam, not rockers. Not that your truck doesn't run good already.

 

I think you'll need headwork to flow that kind of lift efficeintly, your about maxed out as it is I think. Call or PM Allen, he's done some flow comparisons up in conroe and might can tell you when the flow starts to drop off. Too much lift can be a bad thing, I use to have a chart w/ flow numbers for all the heads (5.7, 6.0, 5.3...) but I think I have them on my work computer and I don't go back untill next Tues. Cool chart too, tells you in increments of lift what the heads flow and not just max flow...

 

Storm email that to me if you dont mind I would like to ahve that for reference. If I remember correctly the 4.8/5.3 heads start to nose dive at about 570 lift. Do a little p and p with some 1.8 rockers little higher stall and some better springs stretch it out alittle more and you could concievably hit 11s on that setup.

 

There's no nose diving. They do level off at about 220cfm on the intake. But that holds out to .65'' valve lift.

.5''-.65''
218.0-221.3-222.8-224.6-226.1-228.2

 

No problem I'll try to do it when I get back to work...