I'm not sure I think the only difference is the HO has a 4-barrel carb.

 

If I remember back then... in 86 I think the 4v was late availability. I swear I had an 86 back then and it was a 2v and I was pissed off that I just missed the 4v's.

 

.
.
.
.

okay...i stand corrected. not all 351's were "hi-output"​

1986 4.9 (300 ci) 120 hp @ 3200 rpm 251 ft/lb @ 1600 rpm
1986 5.0 (302 ci) 139 hp @ 3400 rpm 250 ft/lb @ 2000 rpm
1986 5.8W (351 ci) 139 hp @ 3200 rpm 278 ft/lb @ 1400 rpm
1986 5.8 HO (351 ci) 210 hp @ 4000 rpm 305 ft/lb @ 2800 rpm Hi-Output Motor

here's the question, now. how do you tell the difference between the two 5.8L 351's? what are the tell-tale signs of either?​

peace,

b_c

 

the HO will have "5.8 liter 4v H.O." on the air cleaner cover. The base 5.8 will say nothing. Both will show an "H" in the vin. And obviously the H.O. will have a 4 bbl.

 

no the 5.8 was not FI in 1986...mine was originally a H.O. and it was printed on big letters on the air cleaner cover.

 

I have noticed those H.O. air cleaners are worth some money, I have been seeing them on ebay going for over 60$. I am glad mine still looks like new.

 

The H.O. became available mid-year 1984. The difference was the intake, 4180C Holley carb, HO cam (351 4V Marine cam, the 5.0 Mustang HO used the 351 2V marine cam), 17" air-cleaner and larger exhaust with dual outlet muffler. It was only available in C6 auto and in 49-state. The C6 was also calibrated for higher shift points, and a looser stall torque converter, which was later used on the 5.0 EFI C6 applications.

 

maybe late 87 the 351 went to EFI on the broncos.

I know 88 for sure the 351 is EFI.

 

86 was the last year of the carburator
looks like this ... black not blue though ( that was me)

the 351W had the C6, aka no overdrive .. so if you know if it had over drive or not you could rule out the smaller motors ... also Ive never actually seen a 351W that wasnt HO in 86 ... and some sources dont list a non HO for 86 ... so maybe the non HO's were only a few leftovers from 85

 

87 was the last year with a carb. The 87 351 HO and 460 (F250+) still were carbed. The 351 got EFI in late September 87 for the 88 model year and the 460 in Apr 87 just to finish off the 87 model year. The 351 EFI used the HO cam and dual outlet muffler, and later went to single 2 1/2 tailpipe along with a new profile cam in 91 for smoother idle.

 

well...it finally arrived

:chili:

and i was extatic when i saw this

(it's worn, but a little of the H and O are still visible)

and this

(it's a c6...there's no overdrive)

anyway...i'll be starting a thread detailing more here in a few

...thanks everyone for your responses...

:rockon​

peace,

b_c

 

I have an 86 XLT with a bad muffler and tailpipe. I use the old girl to haul my boat and sometimes drive to work. All the parts people and the internet searches bring up a tubular style muffler similar to the one I have except mine is a single pipe and the replacement is a dual. So I'm guessing someone fabricated an exhaust as I am not the original owner. Everything from the cats forward appears stock. Can anyone school me on the subject while offering a cheap solution? Sadly, my XLT is slowly being eaten by iron moss here in SW Michigan. However, the interior is nice. Any helpful advice would be appreciated. I took pics if it matters, I just can't figure out how to add them in the message. I can fix it if I can get the parts. Any troubleshooting advice would be great.

 

... Sadly, my XLT is slowly being eaten by iron moss here in SW Michigan. ...

I have a '96, and someone told me that it was being eaten by iron MOTHS, but either way, welcome to FSB. (And I'm from SE Michigan)