thats an awesome graph. validates what I said earlier.

.578in / .578ex indicate gross valve lift in inches, with your rocker ratio factored in.

 

anyone know what the specs are on the OEM cam?

 

The specs on the 6.0 cam are 197* in and 206* ex I think. The 5.3 will be very close to that. Lift I am unsure of...the 6.0 will be .49x in and maybe .50x out, the 5.3 will be a bit smaller than that.

A good cam for what your are looking for will very similar to the cam that I am running, but scaled for a 5.3 motor. Very strong pull through the entire band, jumps off the line all with the stock converter.

 

and what would that be for a 5.3?

 

Obviouslly I am interested in what type of Cam I need to install to achieve the same performance as that "red" line in the graph.

It sounds like a cam worth doing is going to need me to replace the springs and lifters.

How do i choose springs and lifters?

 

Don't plan on replacing the lifters unless you are removing the heads. For a typical cam swap, just plan on replacing the cam/springs/pushrods. Comp hardened chromemoly pushrods will do the trick.

Springs depend on the lift specs of the cam you choose. If you are keeping your lift below .550 (some will say you can go a bit higher), just use yellow LS6 springs for longevity and a quiet valvetrain. If you are nearing .600 lift, look at PAC 1218 or Comp 918 springs. Over .600 but below .650, look at PAC 1518 or a double spring like a Comp 921.

An important guideline seems to be: don't over-spring or under-spring for the cam you choose.

I also have a 5.3L daily driver Tahoe and am in the cam selection process, trying to choose between the Comp 212/218 low-lift and the Comp 216/220. Both of these are fine with the yellow LS6 springs. I purchased the Comp hardened pushrods and I am also probably going to install Comp's rocker arm trunion upgrade available from Thunder Racing for ultimate peace of mind.

You are where I was in the process a month or so ago. Just keep researching.

 

got any good places that you found that offered good information??

 

Isky 210/216, .532''/.532'', 110*, or 112* LSA. I put the 112* LSA in a 5.3L suburban and it picked up pull from idle to 6K. Also tows alot better.

 

interesting! have a graph?

 

Mainly here and the FSC forum. Two cams you will hear recommended very often for 5.3L trucks are Comp's 212/218 low-lift and Thunder Racing's TR220.

I'm considering Comp's 212/218 low-lift or else their 216/220, which is right in between the often recommended 212/218 and TR220, but makes its power in an RPM range starting only 100RPM higher than the 212/218 (1300 rather than 1200 RPM), thereby allowing use of the stock stall (for a while anyway), whereas the TR220 really needs a higher stall at the time of installation or it will make your truck a dog in the low-end of its RPM range.