First and foremost, that's one Great lookin vette you have. And, as for the 427 tucked under the hood.........................SHAZAME brother.
Got one of those myself in my Mallett. LS6X block with a R after the serial #.
LG long tubes (cermanic coated stainless 3 1/2 into Basssani X pipe NO cats, drifter's 3 1/2 out the back, all stainless.
PURE music to the ear's, great having the wife along as co pilot cause I can't hear her bitching me out above 2,000 RPM, LOL.
Super fun car's for sure ain't they.
We'll have to meet up and go raise some cain with the next Porsche club owner's one day.