How big is your engine? I have tested this enough to know a 1.75 tube on a 340 is on the small side.
We did a dyno test on a 383 chevy. I begged the guy to use 1.875 headers. Of course, he went on the forums and asked there and his buddies all told him 1.750 was on the big side. So he listened to all of them and ordered the smaller headers.
So when I called for the cam, I ordered it for the small headers. It came with a 4 degree split (which I detest) on a 110 LSA. I would have had a single pattern on a 107, but not for the small headers.
We put it on the dyno and it made right at 500 hp like I said it would (forgot to mention I did the heads and flowed them on my bench) and then we put some 1.875 headers on it just for the test. Of course, 3 of his buddies were there to “make sure” we didn’t rig the test.
With the wrong cam it was 20 better at peak and I think it averaged 12 better everywhere. And that was down from what it should have been if the cam was ground for the headers.
I can’t tell you how many times I’ve taken off small headers and put on a big (better) header and went quicker and made more power.