SO with the 1.7" RR i realize that it will limit my options. But for now with the stock cam, would 1.6" be worth it? Getting the 1.7"s, FOR NOW, i think is my best choice, in the future with a cam, i know it will take a specific cam/lobe type, but i'm prepared for that.
I wouldn't hesitate to run 1.7's on a stock camshaft if you put a good set of studs, springs and retainers on it, too. They'll put you at around .510"/.521" lift and you'll pick up a degree or two more effective duration at the valve. Not a bad mod for a couple of hours with the valve covers off, really. But, down the road, it will definitely limit your choices, especially if you intend to stay with stock heads.
Sure, you could limit rpm to keep valve train forces in check if you wanted to run an XFI-like lobe profile like Firehawk was saying, but why...? The reason you're putting the camshaft in there in the first place is so that you can spin it a bit and make some power up top. Plus, even with the 1.6 rockers that they were designed for, the XFI's, for the most part, are generating lift numbers that a stock head will never make full use of this side of hundreds of hours of porting, valve and flow bench work. And all for what...? Buy a set of good heads and move on.
Don't get me wrong. I'm not saying that 1.7's can't be run with a large camshaft. Heck, I'm doing it...! But, you'll just have to be very careful with valvetrain component selection to make sure you haven't created a ticking time bomb. Plus, evaluate what you will have in the end. If you take two of the middle-of-the-road XFI grinds for the LT1, the 268 and the 280, you'll see that with the recommended 1.6 rockers the 268 has lift specs of .570"/.565" and the 280 has lift specs of .576"/.570". To make even moderate use of these lift specs on a stock head, it will require some pretty extensive porting and valve work. Now you add the 1.7 rockers and your 268 is now .606"/.600" and your 280 is now .612"/.606". Even with a proper set of springs, retainers, valvetrain geometry and everything it will take to make it hold together, there's no way that a stock head will make use of these numbers, no matter what you do to it.
I'm not trying to beat up on the XFI grinds. They are good cams, and work well in the right setup. They are just very aggressive over the nose, making valve control a big issue when using them. Adding 1.7 rockers just makes things that much worse, and unnecessarily, I would argue.
Having said all of this, if you wanted to run 1.7's, you could simply have a camshaft custom ground to match your 1.7's when the time came for a cam swap. The cam grinder that I use has over 8500 cam profiles to choose from, so spec'ing out the perfect cam is not hard to do.