TTi step vs. 340 manifolds

Manifolds are street friendly.

Headers are not.

So flow or economic considerations aside, how do you intend to use the car?

I have a race car project already and this car is numbers matching so keeping it street smart. New paint, very good interior, fold down seat option. Very clean.
My goal has been to only do Day 2 mods aside from an MSD distributor and an under dash MSD 6AL, hence the LD340 and not an Air Gap. I was just planning on the intake and header upgrade. Even the stereo is going to stay AM but with a Bluetooth conversion. Really wanting it to look original. I would make an exception on the TTi’s and the period correct LD340.