How high of a lift is able to be run with out computer tuning. I know that tuning should be done, but I am looking for a guess at what the max lift is without problems with idle and engine trouble. Is 214/220 with .539/.564 114 LSA too much? At what point does the head and valvetrain need modification? Thanks for any info

 

I don't think it is necessarily max lift that will give you drivability issues. The duration is what will most affect idle speed, which is really one of the biggest things that tuning cures. I would stay under 220/220 duration, more like the 212/218 for the 5.3. This seems to be the favorite around here for max performance without sacrificing drivability and reliability. I just order the 212/218 high lift 558/563 comp cam for my new 6.0L I will be installing. I also hope to put off a custom tune at least for a while longer, until I am happy with my modding and then I will plan on getting it tuned at that point.

 

You can run a 214/220 with no tuning. You will have to set the idle a little higher. The thing that affects the need for a tune seems to be the LSA. A 114 cam in most sizes can be run with no tuning. Stick with the 114 for better street manners.