If I'm going to be putting something inside an engine like a connecting rod, I'm going to be putting in the correct part. Just my .02
Understandable. You aren't the only one. I was more targeting those who want to increase performance but don't have the aftermarket support. Engines are a dime a dozen, usually not running, but those make the best experimental platforms. My hobby with engines goes two ways: put it on something and drive it around, and try new things.
Won't get very far. Briggs is Briggs, etc.
It's not like Ford parts will fit a Mercury.
This is true in a sense. I think you would be quite surprised at how many parts can fit directly or fit with a little modification.
Some parts of the same brand interchange, some increasing performance, but you are unlikely to find parts from two brands with the same specs.
Well my whole idea is to find the parts that
do fit. There are so many engines out there. There is no way every single one is completely unique. It doesn't have to be internal parts either. It can be as simple as a certain header fitting on another brand block or another model engine of the same brand.
I don't want my idea to be misconstrued. The parts don't have to be exotic mixes. You can mix rotating assemblies among various models of the same design and get a stroker kit (i.e. Tecumseh H & HS type motors). The same goes for heads, valves, cams, etc. Its common practice to swap P&C ignitions with standard coils.