Thanks for the response and information.
I have some information regarding the above numbers for accuracy.
I asked some specific questions and I was sent this:
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The connecting rod length is 6.125" which creates a R/S ratio of 1.5. We do not have any concerns of bearing wear at extended RPM's for your application.
Also, We have implemented new piston technologies including ring packages and piston coatings that improve ring seal and wear.
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As you have mentioned the LS7 also has a 1.5 R/S Ratio, this engine appears to be inline with that. I'm not sure what the average Ratio is for the LS Engine platforms, but this one is limited @ 7000 rpm, and they have done research with this particular package running for extended periods of time at high rpms.
an LS2 is 6.098" rod with 3.622" stroke IIRC, so 1.68 R/S. That engine is IMHO a SBF like a 302 or 351W in overall design concept, but the refinements that Ford should have done v. the mod motor mess they have now. Funny how Ford dropped that engine design and GM picked it right up. The head gasket from a 302/351W and an LS2 damn near lay over each other perfectly - it is crazy. The reason I mention this is 302/351W/460s all had a 1.7 R/S (and probably some other Fords I am not recalling at this minute) and Chevy damn near copied that perfectly as well. The deck height is just a bit taller than a 351 Cleveland and IMHO they should have gotten closer to the Windsor but so be it.
All that said, 1.5 will be fine, I am just not a big fan of such short compression heights in the pistons but they are becoming quite common even in factory engines. Your combo must be right down at 1.060" CH and a typical 347 Ford stroker is around 1.100" for comparison.
I wanted something that would be strong enough to have a lot of fun with, and take it to the track as often as possible, and be able to run the Power Tour easily. Based on the parts that come in the engine, and their attention to detail, this looked like a nice package. Plus, for everything that comes with it a good bang for the buck.
I'm wondering if there is a substantive difference in the acceptable R/S Ratio between the Gen IV and the SBC's?
not necessarily... SBCs were all over the place with R/S ratios v. the Fords being so specific to 1.7-ish or higher such as the 289 (1.84 IIRC) and the Boss 302 had the 289 rod but the 3" stroke so a bit over 1.7.
the dynamics of the engines start to define what R/S is best - a big volume head will work better with a low R/S than a small volume head and the new LS engines have nice heads in general. A 302 Ford for a (sadly) great example of low volume will work better with a longer rod. Generally most of your 7K max rpm engines will work about the same power between 1.5-1.7 R/S... I just prefer the longer rod to get side loads out of the pistons.
Being 11:1 tho', the short rod moves the piston away quickly and makes the combo less prone to detonation which is a good thing... I was seeing slight detonation right at max HP rpm (7300) on the dyno with my 1.85 R/S and 10.6:1 CR on crappy CA pump gas. A shorter rod probably not, but I doubt I would have made the peak power I did with a shorter rod the way my combo is set up.
keep in mind that R/S starts getting more interesting up above 7000rpm so you will be fine for what you are after. It is just a "taste" thing with me so I built my de-stroked 400 to a 1.85 R/S. Early "mountain motors" big blocks (800cube range) used to be down around 1.2 R/S (!!!) but they started increasing the deck heights up to 12" now for many of them, increased the bore space to get the cubes with huge bores (4.7" range!) to get the stroke back down enough to get a decent rod in there.
I am currently running a 400 SBC with 550 hp in my Camaro, and this LS3 427 running with the SS (Hotter) Cam rather than the regular HO Cam, will put out a good 50+ hp more than my SBC, but it idles with a nice lope at 650-700 rpm and 13+ pounds of Vaccuum, whereas my SBC Idles at 1100 rpm with 8-9 Pounds of Vaccuum.
I realize that there are 27 more cubes in the Gen IV Engine, but the manners are so very much different and the mileage one can expect with the LS3 is 3X's that of the 7 mpg of the SBC 400. The LSA in the 400 SBC is 108 degrees vs. 114 degrees in the LS3 427.
the new LS stuff is so nice you won't miss the old 400 
and talk about low R/S, the 400 was the worst small block for that.
I think DSE just picked up one of their, "Race Prepped", LS3 416's. I'm sure they will be seeing a lot more events than I will, however the LS3 427 with a (Callies and Mahle) forged bottom end and ARP fasteners throughout, I'd be shocked if it wouldn't handle quite a bit of Thrashing and a nice kick in the seat to boot.
I am certainly open and interested in your knowledge of engines, and I hope you will give some more particulars of the SBC your running, and of course if you have some specific knowledge of what the big and small differences between the SBC and the GM Gen IV engines are, please educate me.
I look forward to your answers. (Hopefully)
hopefully I covered what you were after. My combo to be specific is a stock 400 2-bolt block converted to splay main 4-bolt 2-3-4, 4.155" bore (+.030"), factory forged large journal 327 crank with aggressive light-weighting, etc, 6" rods and 1.375" CH SRP flattops. When I was in CA the 525HP it made on the dyno (before I went dry sump) would over power my 2500lb mid engine road race car and I figured insomuch and why I chose the 327 crank. Had I to do it over again I would have used a 350 crank with the 6" rod and a 1.250" CH flattop (well it would really be an LS engine or SBF) because I moved to CO and lost around 100HP with the altitude 
but didn't know that when I built the engine 