advise on tailpipes for an 84 dual exhaust conversion

[fgross2006]

I did a dual exhaust conversion a few years ago on my 84 LX 5.0. At the time I laid out so much on all the stuff I needed to do the conversion that I ended up buying the cheapest tailpipes I could find online. This summer I noticed the passenger side right around the bend that goes over the rear end is crumbly. I could smack it with a screwdriver and knock a chunk out if I tried. So I am looking to get a better set of tail pipe. Preferably stainless steel.

Here's my question. Should I go with 3 inch or 2-1/2 inch pipe? In the conversion I had put a pair of magnaflow mufflers with 3 inch input/output. Since the tailpipes I got were 2-1/4 I think (have to measure to be sure) The muffler shop made a 3 to 2-1/4 sleeve to connect the tailpipe to the mufflers.

If I have 3 inch openings on the Magnaflows, should I try to got to 3 inch tailpipe? Or will there be fitment issues? I can go with 2-1/2 if that's the best way. The muffler shop I'm going to said he can only bend 2-1/4 pipe so if I want larger I have to get them online and bring to him and he'll install them.

[85GTGuy]

No experience myself with larger tailpipes, but I've read several times of people commenting on how much harder it is run 3" tailpipes on these cars.... it just gets tight back there.... over the axle, by the brake lines and around the gas tank. It's definitely doable though.... plenty of people have them.

[qikgts]

2.5" all the way. No point with a stock engine. 3" is really big and isn't worth the cost or heartburn IMO.

[ITdude87]

it just gets tight back there.... over the axle, by the brake lines and around the gas tank. It's definitely doable though.... plenty of people have them.

Yep.

It's a tight fit with my 2.5''/Flowmaster kit - When I had my H pipe installed in October, the shop had a tough time getting the tail pipes back properly. In fact, it's still not right on the passenger side and I'll need to make another visit in the spring to get it corrected.

It's rubbing/rattling on the frame in one spot and it's less than an inch away from my fuel/brake lines towards the back. I unplugged the line from the fuel filter and re routed it with a zip tie to get some more room for comfort.

However....That said....I think some of the 3'' tails and maybe even some brands have different bends entirely to compensate from what I've seen in photos. It almost looks like they go under the axle instead of over. If anyone knows for sure please chime in because I've been curious about this also.

Here's a few off the cuff examples I found on Instagram

[85MUSTANGTGT]

I've been pleased with my LMR 2½" stainless tailpipes. Fit great and installed easily (other than the work needed to undo my turndown setup). What I liked most is they're made entirely from stainless, unlike the flowmaster tails that are aluminized steel over the axle w/ stainless tips. They're advertised as fitting '86-97, so I think the hanger arrangement is different from earlier cars at muffler end. My '85 had hanger brackets on the mufflers. The existing ones were in pretty sorry shape, so they were replaced and utilized the hanger s on the the tailpipes.

I seriously considered doing 3" tails, they definitely look cooler, but I was concerned about ease of fitment and clearance with my panhard bar.

ITdude, all the 3" tails I've seen dip down like that behind the axle. I think its just because the bend radius of the pipe is larger and can only get the bends so close together.

[ITdude87]

ITdude, all the 3" tails I've seen dip down like that behind the axle. I think it's just because the bend radius of the pipe is larger and can only get the bends so close together.

Interesting! If that's the case....I'm wondering if that might even solve my vibrating/rubbing and clearance issues, or make it worse.

[85GTGuy]

3" tailpipes just don't look right to me on a stock (or near-stock) Foxbody. Maybe on a bad ass, high flowing motored one.... where 2-1/2" or smaller may actually cost some power. But that's just me.... I've never been a big exhaust tip kinda guy (with the previously mentioned exception, and even then it would be from a power standpoint, not a looks one). In full disclosure, they do look good on some trucks though.

But if they would solve a fitment problem (by going under the axle), then that may make them a viable solution. Should be able to get 2-1/2" to fit okay over the axle though, imo. Gobs of people have... just may take a little more finagling to get it to work.

[85MUSTANGTGT]

No, they go over the axle just like any other tailpipe. I don't think they'll make any clearance problems better. Hell, I thought my 2½'s were pretty tight, probably within ½" in some places, but no noises.

These are a couple of the 3" sets that LMR carries. Both go over the axle and both have the dip just after.

https://lmr.com/item/PYP-TFM15/pypes...it-tfm15-86-93

https://lmr.com/item/FLO-15820/87-93...ized-Tailpipes

[ITdude87]

Roger that thanks Thomas. Come to think, it wouldn't make much sense to go UNDER the axle would it....

2.5'' is awful tight as-is. I can't imagine losing more space with a larger tube unless those bends work in our favor.

I like the looks of 2.5 over 3. I was hoping this was a magic bullet for the clearance issues.

[qikgts]

Super common to see under axle tails on coyote swapped, IRS equipped Foxen...

[fgross2006]

Thanks for all the responses. I think 2.5 is the safest way to go. Any suggestions on a good stainless tailpipe for 86ish since mine is an 84 customized to an 86 H pipe, rear brake lines conversion etc.

[85MUSTANGTGT]

These:

https://lmr.com/item/LRS-5212PR/86-9...teel-Tailpipes

Best bang for the buck IMO.

[gr79]

304 and 409 ss
At work, they brought in new automated ss tubing bending machinery. Prob 6.
Pipes were 2.5" or 3" for new Cadillacs. Bending machines were as big as a one car garage.
Smaller ones prob did flaring, etc. Straight tubing came in rack loaded.
Was transferred to a new facility so never got to see how fast they work.
Bending hydraulics and high voltage electrical were much larger than in muffler shops.
Factory did it all. OEM converters, mufflers, and complete robotic welded systems head to tail.
New facility built large oem converters for heavy diesel trucks and off road machinery.
Is amazing how fast riggers set up and test run new production machinery lines.