I am in the process of putting a '71 iron block 427 SO in SPF 2068. Like every install I suspect it has its challenges...
I think the biggest issue between a 427 and a 351 or 460 install is the quality and completeness of the SPF runner kit versus the other builds. I suspect this has a lot to do with an earlier post suggesting lower 427 installs. That being said the guys at Dynamic in Ohio are great and helped a ton through this process.
In particular, I found the SPF 427 engine mounting system very low quality design. I ended up purchasing a poly kit from an small fabricator who modified the SPF 460 mounts. Much better solid connection.
I also found the rubber radiator hose system inadequate and difficult to navigate the difficult logistics from the engine to rad. Ultimately, went with a cool flex brass line with rubber adaptors which could be massaged into appropriate shape with proper reducers/adaptors and won't crush under load.
I also chose to go with AN12
oil cooler lines with Mocal thermostat. The front brake splitter is head on the
oil plate making this a difficult logistic without moving the splitter.
I liked the flange system on the headers to sidepipes versus the clips/ fit system I have seen on other cars.
However, overall I am very impressed with the quality and craftmanship of the SPF.
SPF 2068