I am installing 2.5" pipes on my 65 Convertible and I am wondering what the clearance is supposed to be between the pipes and the floor as the pipes go over the rear axles.


I purchased Flowmaster prebent pipes for a 67 Mustang GT as they were the closest to my 65 with a GT sytle valance in a 2.5" diameter.


Does anyone have the measurement, have pictures, or have done this in the past.


Thanks!!

 

Some points are less than an inch. With 2.5" pipes, it'll be a miracle if you get that. As for the pipes in the tunnel, I'll be really interested to see if they will fit above the plate at all.

 

You are right in that they will not fit completely above the plate, especially if you use an H-Pipe. Currently, they are about .5" below the plate. I have Global West subframe connectors that should help. But I am thinking about whether I want to to:

A. Fabricate a spacer to lower the plate.
B. Create a cross brace that bolts to either the subframes or subframe connectors.

Back to the tailpipes; you feel that the pipes beiwng within a 1/2" or so of the the floor is okay? I am concerned with rattles.

 

I have the Flowmaster prebent tail pipes and I can tell you that they don't fit worth crap. I had to have my muffler guy modify them to fit straight. Sometime in the future, I am going to redo them I think.

I would advise just having a good exhaust shop make the tail pipes you need. Just make sure they do not have a bender that leaves the ripple effect on the pipes.

Ideally the exhaust should be at least an inch from the bottom of the car, but if its a little closer I don't think you'll have any issues.

 

The center plate is what joins the lower platforms together to form a torque box joining the two rockers together. I wouldn't mess with that.

I have another car where the exhaust passes through the frame in six places. Exhaust rattles were practically standard equipment, with clearances less than 1/4". However, with careful adjusting I currently have no rattles.

 

Sort of my thinking, except I will have to "mess with that" some. The convertibles have the plate (whereas the coupes/fastbacks don't) because they don't have a roof to keep the left and the right together.

I feel the subframe connectors will strengthen the chassis, but mostly in the front and back. The bars are big enough to not twist much so they should add some side-to-side support but I am thinking that adding a brace is in order.

If anyone has done this already - on a convertible - I would love some advice.

Back to the exhaust: You must have worked very hard to get 1/4" clearances to not rattle. You must be very patient.

 

Do you remember what the muffler guy did? I was thinking about cutting the pipe as it goes up from the back of the muffler, removing about an inch, and then using a band clamp which would allow me to both adjust the lenght and rotate it slightly.

Thoughts?

 

He cut them so he could twist them and he had to slightly modify the bend in them.

 

Sounds like what i am planning. How far from the the bottom of the floor do you estimate the top of the tailpipe is? Do you have any rattles/contact in that area?

 

My exhaust guy bent and built the front part to the mufflers (x-pipe, pipes to 4.6 manifolds) but bought pre-bent 2 1/2" tail pipes. I don't know where he got them but they fit pretty well on my 65. He did have to tweak them a little to go around the Explorer rear. I guess he probably got them from a local wholesaler.