Not to hijack your thread, but the chinese made American engine parts are kind of hit and miss, with "Cat" being the bottom of the barrel. Be careful where you drop your money on "good deals". I purchased an "SFI approved" BBC flexplate made by Cat and luckily I inspected it thoroughly before I installed it and found 2 of the welds that attatched the gear to the plate to be cracked but still attatching the 2 pieces together. I contacted the internet seller from whom I purchased the part. The guy I talked to said he would send me a Scat brand replacement instead of another Cat, I asked him what the difference was and he said that their company recieved about half as many returns on the Scat brand compared to the Cat brand. I said no thanks and just asked for a refund, he then tried to give me a set of free chinese roller rockers along with a new flexplate if I "would like to give em a shot". I still said no thanks and got my $45 back. Maybe I'm being a little "glass half empty" but I'd be willing to bet those rockers were yet more crap they had recieved on a return.
Unfortunately, unless you have mega-bucks lying around, if you want to build a stroker you've got about 3 options Cat, Scat, or Eagle. I havent heard too many horror stories about Eagle, and they seem to be pretty common place in stroked motors, along with the 4340 scat's. I don't know of anyone thats used a Cat crank personally, but if the quality in their cranks is anything like the quality in their other parts I can see why. Do a little research on their reliability and quality before buying such an important part. It may sound like a good deal, but I'd hate to see anyone throw the money it takes to build a BBC down the drain because they were trying to save a couple hundred bucks on a crucial engine part.
One problem that you run into when using a short rod on a stroked engine is the rod crank angle. To simplify it as much as possible a longer rod is beneficial in two ways as it relates to the effeciency of an engine. The first being the amount of time the piston spends at TDC. A longer rod is going to spend more time at TDC than a shorter rod allowing for more pressure to be built up in the combustion chamber before the power stroke. The second benefit of a longer rod is the amount of force that gets exerted on the cylinder walls. The longer rod gets to spend more of its energy moving up and down in a cylinder bore instead of pushing the piston against the wall of the cylinder creating more wear and friction, which in the long run equates to an engine not lasting as long do to higher stresses in the rotating assembly and an unevenly worn cylinder bore.