LS1 technical questions
most people seem to agree that 2000 and earlier engines are limited by the rod bolts to a max of 6200-6500 RPM, depending on how far they are willing to push it. Upgrading them to Katech or ARP bolts seems to bump that high enough that the valvetrain will be your next worry. Stock valvetrain components that might otherwise limit the engine would be swapped out when you do the cam. Hydraulic rollers are still rpm limited by weight and lobe profile, but 7200+ isn't unheard of.
also the limits of the stock 4L60E(i know its not alot but what is it?)
the stock tranny is limited by the RPM it will withstand, which is not much more than 6000 rpm. Most cams are going to make peak horsepower above that, so it would be wise to consider upgrading the tranny and the converter
what would be the highest duration cam i could run without having to run a stall converter?
a stall converter is generally good for 3-4 tenths on a relatively stock car. I would research converters, because not too many performance cams work very well without at least a 3200 stall converter. If you select a cam around the stock converter, you aren't even going to get close to 400rwhp without investing in some very good heads.
whats the limit on the rear end?
With an A4 and street tires, you have very little chance of breaking the stock rear, even less on the stock converter.
I'd recommend searching for cars that perform the way you want and note what parts they are using to get there. Then find out more about the tranny hard parts and converter selection in the automatic forum.



