[awsum67]

I did a search on this BB to find out if the pre-68 RA manifolds will fit a 68 & later car (and vice-versa). There are conflicting opinions. One source said they will fit interchangeably and one source said he had a conflict on the driver side frame when he tried to use the 67 and earlier on a 68 GTO. I know that 2 variants are made. One for pre-68 and one for the 68 and later years. What are the physical differences between the two versions?

[Geoff]

The 67 RA manifolds use 3 bolts each side to secure the exh pipe. On the 68 & later manifolds, the RH side retains 3 bolts, the left side uses 2 bolts.

[awsum67]

Geoff, thanks for the information. Are there any differences that would limit their application between 67 and earlier versus 68 and later.

[Geoff]

I had the 67 version RAs on my 66 GTO, with no clearance problems. I don't know about the later models.

[goathead68]

I have '67 RA manifolds on my '68. The downpipe flange on the LH side comes thisclose to the frame in the area of the lower A-arm rear attachment point, but does not touch or rub.

I did have to take a large pry bar to move the engine a wee bit to get the front flange bolt tightened, but, like I said earlier, there are no other issues. I may have ground the front of the flange down on that side as well, but it's been so long I don't remember if I did or not.

The car is not currently where I'm at, but when I get a chance, I'll try to get a picture or two of the manifold on that side to illustrate.

[TCSGTO]

I tried putting 67 manifolds on my 68 and there wasn't room for more than a 2.25" pipe. And even that was too close to the frame near the lower control arm. With engine torque it would have probably made full contact. I didn't run them and eventually got the 68 & up ones.

[Ccass]

There are different brands of exhaust manifolds. The 2.5" HO/RA manifolds that PY is releasing in the Fall, while 67 HO, will fit 68-72 cars.