Thanks for all the replies! Anything above 50, and it would progressively fishtail. Getting passed on a 2 lane highway in some low visual misty twisties at 3 am by a logging truck doing 80, blew!
I ordered a TV cable kit made specifically for a 700r4 backing a 5.3L.
I am down to the final fuel system parts, fuel pump upgrade and adapting fuel lines. Also need to have the computer reflashed.
I’ll be starting my pic taking and will start a build thread soon.