[PurelyGTO68]

Originally Posted by 68ragtop

Mine fit nicely, 4 speed. But I don't think I have any flattened areas. But again, I bought mine many years ago. Not as refined as the newer gardner systems. I recall talked to him a while back & mentioned something about black head pipes too, but maybe that was a ram air/ HO thing only.

Looks like you are correct. Their website says that HO (and thus RA) manual trans cars had 2 1/4" headpipes where standard engine and automatic models had 2" pipes. The HO and RA manual trans exhaust systems had the flattened portion to clear the crossmember I suppose. Here is a link to their website. You can see the area that is flattened.

https://www.gardnerexhaust.com/exhau...xhaust-system/