Feedback on Boss i'm interested in

[pavestone2460]

Hi all,

New user to the forum from Australia. I haven't put a post in the introductions section yet because I don't own a Mustang - hoping to change that soon though. I've had a fondness for the 71 - 73 models for a while but they're few and far between down here. A Boss 351 has come up for sale near me though and I was hoping to get some feedback on it - https://www.gassportscars.com/used-vehicles-albion/view/1971-Ford-Mustang/29954052

It looks original to me with good options and colour. It has a rear spoiler, magnums and a console which aren't on the option sheet. Engine bay looks like it should. Anything I'm missing? The ad talks about it being a "Mach 1 Boss 3351" and the VIN in the description doesn't match the VIN in the paperwork in the pics - hoping those are just typos.

I'm wanting to go and inspect this ASAP and I'm just trying to get together some info on the unique Boss parts so I can verify they're correct. I've found this article here https://www.motortrend.com/how-to/1609-boss-351-engine-detailing/ and wondering if there's any other references I should be looking at? Is it possible to find the VIN on the engine and transmission to verify it's matching numbers or are they in hard to reach places?

Final question - how "streetable" are these cars? Ultimately I plan on just cruising in this thing every couple weekends, nothing crazy. Having never driven a car with 3.91 gears or a mechanical cam, I'm not sure what the experience will be like.

 

[Sheriff41]

Welcome Pavestone, and howdy from Texas!

Boss 351s are great cars! That said, there are things you'll want to verify.
- Check the body inside and out for rust, check the floor of the trunk and the taillight panel, check the cowl area
- Check for the correct carburetor; replacements are hard to find and pricey
- Check for the correct distributor, oil dipstick, rev limiter, etc
I'd recommend you check in with the crowd on www.boss302.com and talk with the members in their Boss 351 forum.

The one you linked looks nice in the pictures and, based on US sales recently, looks to be fairly priced.

Keep us posted on your hunt!

 

[Sheriff41]

Here's the link to the www.boss302.com's Boss 351 forum: https://www.boss302.com/smf/index.php#c7

 

[ib4stangs]

If you like it, ask seller to put it on the lift to inspect for rust before singing any papers...

 

[cv_72mustang]

Welcome, Search for this title on this site that one member recently posted and view the video. Car flipper cautionary tale

 

[Stanglover]

I'm for sure no expert here, but looking at the pics, it looks to be "correct", but then someone could have spent a lot of money to make it LOOK correct. From my very limited knowledge not having owned a Boss1, (I wish!) I would say without doubt go look at it and don't get sucked in by emotion. It's a very expensive business deal and the price is padded for profit. Inspect everything, look for something out of place or wrong.
Unfortunately finding VIN numbers is not easy. The block number is located at the back left side block, just under the head. A mirror and camera might get it. Gear box ought to have a tag on it that reads RUG-AW1 for the CLOSE RATIO box it should have. However this could have been changed too. Carb tag; D1ZF ZA. Rear axle tag; 3L91 WFD-D2 with door data plate (sticker) letter "V". The distributor I can't find a number listed, but it ought to be a dual point. The carb MUST be a "spread Bore" i.e. the rear secondaries are much larger than the primaries. The intake should be an aluminum one with D1ZX-9425-CA. The body number are not possible to see without pulling a fender back, and that isn't going to happed at a dealership. Here's a pic of what I mean.
Other than that, it's how you feel about the car and the deal, but for that money, I'd want to be damn sure. Others will for sure add or correct my thoughts.
Good luck and welcome regardless from SW Ontario, Canada.

EDIT: Further discussion has revealed an error on my part re, gear box tag. It probably should be RUG-BJ which is a WIDE ratio box. My apology.

 

[Stanglover]

Welcome, Search for this title on this site that one member recently posted and view the video. Car flipper cautionary tale

https://7173mustangs.com/threads/car-flipper-cautionary-tale.43432/unread

 

[rvrtrash]

Welcome. The VIN being different in the description may just be a typo. A few things I noticed are: Boss 351 hood stickers just said "Ram Air" not 351 Ram Air. The mount for the spare tire is missing some welded on parts to attach the threaded hook to. The air bottle for the spare is missing. The rev limiter is missing the stamped decal, so it might be a non functional repop. In response to an earlier post, the transmission tag could also be AV1. The block serial number is at the top rear of the block on the left. It's visible if you really work at it. The transmission serial number is at the top front on the left, where it bolts to the bellhousing. The dealership says it's numbers matching, so I'd ask for pictures of the VIN from both locations. Let them crawl over the fender getting them. I'd be concerned that it was originally a midwest car and there are no pictures of the underside. I'd ask them if you could put it up on a lift and inspect the bottom for rust. The fact that it looks freshly restored, it's not 100% correct, and things have been changed, tells me whoever did it, didn't do their research. I'd be extra cautious. Definitely check the part numbers on the carb and intake. If you have to find the right carb, it's at least a $5-$6K (US Dollar) item. I've seen as high as $8K.

 

[Stanglover]

Not to be controversial to rvrtrash, but the RUG-AV1 is wide ratio. The RUG-AW1 is close ratio @2.32, BUT I just noticed the RUG-BJ is actually listed in Marti's Tag Book for the 71 Boss351 and at 2.78 would make it a wide ratio. Something seems off there as I thought the Boss351 had the close ratio box, period.
Can someone else confirm?

 

[giantpune]

Seller also calls it a "mach 1" several times. Its a fastback, but I dont believe it counts as a mach1. Its a boss. The "02" body code in the VIN is just a fastback. Mach1 have "05" body code.

It does appear to be a recent restoration as opposed to an all original car. Looks like they even did the lettered stickers under the hood. Which, to me, always seemed odd. Not every car got those stickers. But some guys really want to add them when doing a concourse style restoration, even if the car rolled off the assembly line without them. And then some of the other stickers under the hood are very white. Far to white to be the real 53 year old ones.

There doesn't appear to be anything wildly wrong with it. But you're just seeing the photos the seller wants you to see. When you see when you get the car up in the air and start nosing around on your own could be a completely different story.

 

[rvrtrash]

Not to be controversial to rvrtrash, but the RUG-AV1 is wide ratio. The RUG-AW1 is close ratio @2.32, BUT I just noticed the RUG-BJ is actually listed in Marti's Tag Book for the 71 Boss351 and at 2.78 would make it a wide ratio. Something seems off there as I thought the Boss351 had the close ratio box, period.
Can someone else confirm?

Well here's my Marti.

 

[Stanglover]

Well here's my Marti.

Well that is interesting indeed. Not being a Boss owner, I, like others not so fortunate, can only go by the data and information we get from listings and books like the Marti Mustang and Cougar Tag Book.
Personally, I was under the impression that ALL Boss351's had close ratio top loaders. I do have one friend with a Boss, I will check with him for my own education.
Thanks for posting your Marti.

 

[rvrtrash]

Well that is interesting indeed. Not being a Boss owner, I, like others not so fortunate, can only go by the data and information we get from listings and books like the Marti Mustang and Cougar Tag Book.
Personally, I was under the impression that ALL Boss351's had close ratio top loaders. I do have one friend with a Boss, I will check with him for my own education.
Thanks for posting your Marti.

You're welcome. I seem to learn something new all the time. That's what makes the hobby interesting, and one of the reasons I enjoy this site.

 

[Billw69]

Mine is original, and wide ratio.

 

[Stanglover]

You're welcome. I seem to learn something new all the time. That's what makes the hobby interesting, and one of the reasons I enjoy this site.

Thanks and yes I agree. My signature says just that. "I learn something new every day."
Going back to the quote in the Marti tagbook, RUG-BJ is listed as a wide ratio at 2.78:1 in the Boss. Now, my thought was an error, but now, probably not. That now poses the question, "what is the difference between a RUG-AV1 and the RUG-BJ?" Hmm.

 

[Mac]

One alternate source of info to consider is the Mustang Club of America (MCA) web site. On this site you can look at the actual judging sheets for the '71 Boss 351 to see all the critical things to be aware of as well as contact info on the Boss certified judges.

 

[72MustangSprint]

One alternate source of info to consider is the Mustang Club of America (MCA) web site. On this site you can look at the actual judging sheets for the '71 Boss 351 to see all the critical things to be aware of as well as contact info on the Boss certified judges.

Never would’ve thought to do that. Nice tip

 

[rvrtrash]

In reference to the RUG-BJ transmission code, I seem to remember something about the '72 HO using a BJ or BJ1 transmission. Might be my faulty memory or maybe that's where they derived the "Boss" reference. Maybe the MCA site spells it out.

Late edit.
I checked my copy of the MPC. I'm including two screenshots, showing the AV1 as the wide ratio and AW1 as close ratio. You can also see that the BJ and BJ1 show '72 part numbers, with a change date of 12/1/71 (1972 model year), and the BJ being a replacement for the AV1, so some late '71's may have received a BJ transmission, but it appears it was meant for the '72 model year.

 

[MikeGriese]

I'm always surprised when people to go to all this trouble to restore a car and forget to paint the steering column. Lots of key rash under the ignition switch. Definitely look under the car, tap metal things to make sure they sound like metal, use a magnet to check for bondo, get a paint thickness meter and check paint thickness anywhere low on the car - be suspicious of everything. Ask questions. Don't be afraid to walk away.

 

[Stanglover]

In reference to the RUG-BJ transmission code, I seem to remember something about the '72 HO using a BJ or BJ1 transmission. Might be my faulty memory or maybe that's where they derived the "Boss" reference. Maybe the MCA site spells it out.

Late edit.
I checked my copy of the MPC. I'm including two screenshots, showing the AV1 as the wide ratio and AW1 as close ratio. You can also see that the BJ and BJ1 show '72 part numbers, with a change date of 12/1/71 (1972 model year), and the BJ being a replacement for the AV1, so some late '71's may have received a BJ transmission, but it appears it was meant for the '72 model year.

Yes, that is what the Marti tag book shows also, but with out the date change. The book also shows for the 71 4V CJ, AV1 or BJ. I wonder what exactly the difference between the AV (AV1) and the BJ (no funny jokes here) was if any?
What I find odd, is the fact that the Boss had the wide ratio box. My 71 Mach has the wide ratio box and I sure as hell wish it had a close ratio for better cornering control. Also it blows what I thought I knew about Boss 351's out the water.