My 318 Build with questions

I like it too. And if you do the looser TC like will-run sorta hinted at, then I would try the 2.7s . But make sure it is SureGripped, cuz it will last a lot longer.
Don't let anyone talk you out of big pipes.
I ran a teener for 4 winters (mid Sept to late May)with dual 3 inch pipes, all the way to the back bumper. Best LC factory longblock I ever ran. I think that engine saw those pipes as straight atmosphere, maybe better than. Ok maybe not, but you get the idea. At least run some big pipes to the mufflers; I guaranty you won't be sorry.