Harp 1

Gentlemen just a quick question. I found an envelope of cash in my drawer I forgot I had and want to put dual exhaust on my 75 Delta 88 Royale Convertible/350 4 barrel. It probably has one more season left. Is it wrong or just a personal preference?? Any thoughts positive/negative on getting the stainless?? Thanks Matt

Olds64

Of course it's not wrong. Do whatever you want, it's your car. Dual exhaust is one of the easiest upgrades you can make that will give you a lot of satisfaction. It can tremendously change the character of your car. FWIW, I have dual exhaust, headers, an X pipe and glasspacks on my 71 98.

jcdynamic88

i think i left that envelope in your drawer.put the duals on it,it will be like getting a new car

joe_padavano

You will need the double hump trans crossmember from a 1971-74 Olds full size. Your 1975 model will only have a single hump crossmember.

redoldsman

A nice dual exhaust system will put a smile on your face. It is even better with a convertible.

MDchanic

Scott at ClassicExhaust makes a decent-fitting dual exhaust system for that car for a good price.

As Joe said, you'll need the pre-catalytic transmission crossmember.

- Eric

Harp 1

Ah I forgot about that small tidbit. Besides the parts wanted forum can somebody point me in the right direction where to find such an item?? Thanks Matt

Inline

It necessary dont need dual-hump crossmember if done well.
My Cutlass ( 76) has dual exhaust with single-hump exhaust ( i have the correct dual-hump nowadays cleaned and painted, waiting someone to install it).
Other pipe simply does turns to go under the crossmember. Its not pretty, but someone did it so well that it doesnt rattle against crossmember, and with stock-height suspension i havent hit it to ground even once. 2.5" exhaust.
But i admit, its ugly and you can even see it when standing far enough from car.
And thats why i am changing it, too.

But just to throw an idea to air that it might not really be necessary, if you can live with it.

Kennybill

As I would be putting dual exhaust on my car, my Father would comment "double trouble." That being said, fabricating/changing to the proper cross member won't be to bad. I used Classic Exhaust recently and was satisfied. One of my future projects (if I have enough life left in me) is to put a small block in one of my 1967 98's. I found the correct small block manifolds (thanks to Glenn, Copper 128) but I needed a correct crossover pipe. I called Scott, he made one up at a fair price. He's 45 miles north of me. I have A-body headers with an H-pipe on my Delta Royale. Good luck with your Delta.

Harp 1

Guys will the dual hump cross member from a 70-72 Cutlass HT fit my Delta??

joe_padavano

Your car is about six inches wider than a Cutlass. What do you think?

jcdynamic88

that's a no

76olds

I'm just going to throw this out here for you, I put 2 1/4 duals on my 76 cutlass without a dual hump cross member.
I have some exhaust pics in my photo album that you could have a look at if your having a shop custom bend and install your system.

Eric

jcdynamic88

i have done many g-body dual exhaust conversions by notching the left side of the cross member,you can actually cut a pice out of the bottom/middle and turn it around and weld it back in,it allows enough clearance and you don't see it when looking at the car from the side but it is more work and never as nice as having the right cross member.i would recommend the right cross member if it's available.

76olds

The first set of duals I had were 2" off the manifolds on my 76, and we just flattened the top radius of the pipe a little to clear, that worked out Ok for my performance level prior to going with headers and a 2 1/4 pipe.
Never as nice as using the proper cross member for sure, I just made due with what I had.
Eric

olds 307 and 403

I got duals custom bent on my 88 Cutlass, all under the single hump cross member off of Sanderson shorty headers. Plan on flip flopping the exhaust, I will notch the 88's crossmember for the 70's tiny duals.

bigdooly

As Joe stated the 72 , as well as all 71-74 b/c bodies came with the double hump cross member.
75 76 did not. Dual exhaust was not offered after 74. The 75 and 76 required modification to the member, or use an earlier 71-74 member.
the right side manifolds dump out into single exhaust with a crossover pipe from the left. Many years ago I sent my 75 out to a midas muffler in Brooklyn N.Y. and they blocked off the crossover on the right manifold. I'll post a picture later. I threw out the modified crossmember, and put one from a 72 in my chassis. The manifold i still have looks like **** but it worked. I will use Thornton shorties when I put it back together.

Joezilla

Headers for a 1975 442 will fit and clear the shift rod.