1969 shelby & 1969 boss 429

Dave,

To answer a small part of your question regarding performance, the camshaft was the most restrictive aspect of the Boss 429 engine. Because of having to meet the then emissions regulations, just when the heads were starting to breath, the engine ran out of camshaft. I sure that others who post here and are more knowledgeable than I am will be able to add much more.

 

I've never owned a '69 Shelby, but I have owned 3 Boss 429s. The major restrictions for the street Boss 429 were many...camshaft, 735 cfm carb (smaller than a Boss 302), very restrictive emission control system and exhaust system. If you open one up they are great performers. Boss 429s left Ford as sportsroof cars and were sent to Kar Kraft for modifications including widening the shock towers for engine clearance, moving the drivetrain forward over an inch (this is why you need a special adapter for the shifter and there's no fan shroud), relocating the battery to the trunk, replacing all of the front suspension components on the '69s (the '70s shared the Boss 302 suspension for the most part), etc. I'm not sure the Boss 429 was built to outperform the Shelby, at least I've never heard that, but they were built to homologate the engine for NASCAR and also to compete on the street with the 426 HEMIs and 427 Chevys, Bunkie wanted to have a dog in that fight apparently, to bad they choked it down from the factory. Hope this helps answer your questions, I'm not an expert even though I've owned a few, but I would be happy to help answer any other questions you may have about Boss 429s.

Edit - Let me know what pictures you would like to see and I'll post them.

Jeremy

 

Have had both and in general

1- the Shelby was a better driver and was faster on the street with its low end torque

2- both cars are, in general, not the greatest drivers as they are both front heavy though the Shelby was a nice highway car (Boss's low rear gears limited its speed)

3- Shelby got more attention in general since it "looked" more different (sure there is an teacher somewhere cringing at that usage) than a regular Mustang

Just some observations

 

Here's a lot of information on the Boss 429.
Frank

Boss performance




Two 427 tunnel ports One Shelby aluminum 427 and One 428

 

I think you are neglecting the fact that the Federal Government enacted the "Clean Air Act" the year before-1968. So, the Manufacturers had to file paperwork with the goverment to ensure that their cars, from the 6 cylinders to the Boss 429's met the standards. To acheive this, air injection pumps, smaller carbs, different cams where all utilized to meet or beat the standards.
Whatever it took was Fords way. There was no deliberate restrictions on any engine.
And, the Boss 429 was sold to mainly two types of customers. Those with money who could afford a $5000 plus car, and to street racers. Many many Boss 429's ended up in the hands of street racers. All of them will tell you that once the carb got bigger, the air injection pump got lost, and the cam was replaced, few cars could touch it. Bunkie Knudsen, the Ford President at the time wanted that engine in a prestigious car. Me, I would have put it where it raced, the Fairlane/Torino line, but thats me.
The Boss 302 was the SCCA auto crossers car. It ended up in the hands of those who desired excellent handling, along with a high performance engine.
The Shelbys where built for the specialty market in mind. It is a cooler looking Mustang, handled well, and, with the 428, scooted pretty well.
Don't try to read too much into the horse power ratings, Ford did what it could do to cover as much of the market as there was.

 

Not to mention that the mfgs. were running scared of putting too much performance on the street...because the ins. companies wouldn't insure them and/or lawsuits.

 

I have owned my 67 GT350, 70 Boss 302, for 26 years, also a 69 GT500, and a Boss 351 in the past....
My favorite car has always been my '70 Boss 302....it handles better, stops better, and is more comfortable than any of the others....The 67 GT350 would be my second favorite, and always draws a crowd..

The Big block Shelby, had terrible handling, and was not that much faster in a straight line...

Mark

 

In a straight line the Boss 429 would outrun a Boss 302. I've owned both including a W-Code Boss 302 and the 429 would pull away from it in a straight line. The Boss 429 block is a special block, Frank can correct me if I'm wrong, but I believe the oiling flow and water flow is different and I'm sure there are other differences as well. ALthough I also know that people have modified a 429 block to use Boss 429 heads. I have pictures of both cars, what exactly are you wanting to see, I'll post whatever you want. By the way, the Boss 429 gets a bad rap, but when it gets put to the test it performs well. It was the fastest quarter mile car in the Dream Car Garage Musclecar Shootout which included a Hemi Challanger, Hurst Olds 442, 455 Buick, LS6 Chevelle, AMX, etc. running in the 13s with all smog etc. My understanding is that the public just expected more from a race engine, that's where the bad rap comes from. If you're in Indiana sometime I'll take you for a ride in an unrestored Boss 9 and you can decide for yourself!!!

Thanks,
Jeremy

 

Dave,
You're more than welcome. I actually don't have any good photos of the shocktower and suspension modifications, but I may know where to get some, I'll post them if I find them. The shock towers were actually cut out and modified towers were welded back in their place (I believe initially this may have started at Kar Kraft and then later at Ford). As far as the suspension, on a '69 essentially all of the parts and pieces are one off's and it gets very expensive if you're missing them. I'll work on some more pictures, there are some really nice Boss owners who go to Carlisle and Hershey as well, if you would like to meet up with some of them I can work to get their e-mail addresses for you and I'm sure they'll show you everything you want to see on a Boss 9 when you come across the pond! Let me know.

Jeremy

 

Hi Dave, I am in the U.K. There is only one Boss 429 in the U.K . thats a 69 .
There used to be more but they have gone to other climbs !!
Where are you based ?
Whats the shelby you are restoring?
THX, John

 

Here's the Boss 429 shock towers...courtesy of Frank!

 

Boss 429 in UK

Sorry to perpetuate the UK theme to this thread...

I have seen 3 Boss 429s over here - the Blue '70 owned by USAutomotive (now gone back to the states I think), Paul Edwards Black '69 (now in Switzerland?) and another '69 which I think had a 390 motor in it.

Paul's was an interesting car as it came to the UK with a 427 SOHC motor in it! When this blew, the then owner had Jack Roush prepare a road/race Boss 429 engine for it. This had solid lifters, single plane manifold, full hemi heads, headers and an 850 dp holley.

When Paul got it, the car was a bit rough, and the engine hadn't been installed or set up very well. We stripped and restored the car and had Clive Bond at Ultimate Race Cars rebuild the engine. With slicks and 4.11 gears I recall it running low 11s which equates to about 460rwhp. From a 40mph rolling start it would out-drag my '65 HiPo without shifting out of top gear!

Happy days...

David

 

Hi

Just an update, but at present I know of at least 3 Boss 429's in the UK. Although a couple went out of the country some years ago, others have made their way to the UK and into private collections.

Paul

 

Hi Paul , and David , I have tracked Boss 429 cars in the U.K what was here has gone out of the U.K .
I believe and no of one The Sorn castle car .
What others do you no of ?
THX, JOHN