Michael;

I don't know about the feasibility of using those parts from a fitment perspective but as for the lift, I think you should be okay if you have the stock 5.0 HO flattop pistons with valve clearance eyebrows.  I used stock replacement pistons when I rebuilt our's and I'm now running AFR heads with bigger valves than the E7's and I have a comp cam that gives 550 lift on 1.6 rockers. I measured valve-to-piston clearance with clay when I built the engine and as I recall it had over .120 clearance.  The 1.7:1 rockers will give you around .468 lift with the stock HO cam so it should have plenty of clearance.  If you don't have the stock pistons or cam then...none of this means a thing.

BB 
 

PM sent... That's probably the better way to go.
Still, you have to admit that the concept is interesting.  I bet it would work.

It really depends on the cam and heads.  If the heads have a weak intake port, and you're running a single pattern cam, then running 1.7s on the intake only often helps, while the exhaust doesn't need the additional lift. 

A good aftermarket head has about a perfect intake/exhaust relationship in terms of flow, and in those cases there is no benefit to running different ratios on the intake and exhaust with a single pattern cam, BUT a dual pattern cam designed for a closer to stock I/E relationship could still see a benefit.

In general, running different ratio rockers intake to exhaust is another tuning tool.  Ideally the heads and cam would just be right and there's be no need to do it, but if they aren't it becomes another work around that can help you get the most out of your combination.

Again, ideally, and I learned this from Joe Sherman in the Engine Master's Challenge, you want to run the lowest ratio rocker you can.  In other words, grind the cam so it has the proper duration and lift, rather than increasing the rocker ratio.  The reasoning is that the higher the ratio the higher the leverage in the system and the more stress everything is under.  It also becomes harder to get a good contact pattern on the valve stem because the length of travel is greater the higher the ratio.  A lower ratio rocker runs with less stress in the valvetrain, less side loading, and therefore less friction and heat.  Like anything else, what doesn't get consumed in friction and heat translates into increased power output.  Joe had an engine one year with a 1.3:1 rocker ratio, which of course won the challenge.  That guy's really, really smart. 
 

I didn't now that, I just saw the obit., guess he passed back in February.  Another of the old guard goes to his eternal rest.