Hooker Super Comps on my '68 RR Hemi 4speed. 438", big cam, pulls like crazy to 7,500, where I run out of stones and pull the handle for the next gear. 2.5" full exhaust. Sure doesn't feel like there's much if any restriction.
Laid them in before the motor, no fit problems, manual everything. A bit tinny from the primary segments until warm.
Coated after purchase, been in there since 1988, still look good, but the car's never been in the rain.