I used the TTI 1 3/4 inch headers with the 512 in my '72 Duster. I think 1 3/4 is big enough for a street car with mufflers. Guess it just depends on your pain vs. reward calculation. You should be able to run 10's with the 1 3/4 headers but if you think you'll be going faster than that then step up to the larger headers. I tried the larger step headers and they were just so big I sold them and went with the 1 3/4 tubes. I can at least work on the car with the smaller tubes. With the big tube headers it was hard to access things.
View attachment 1715360231
