Mmmm GM 427 ...
yes that will get the front down.
I drove a SPF with a 351 stroker at Costa Mesa - Hillbank - and it was a nice car. Later at the Run N Gun I drove one with a Shelby aluminium block. Fun also!!
The GM 427 will be great. I think Garrett - Justbetter - is or has placed one in his SPF..
Again, a really neat Cobra hope you have lots of fun..