Stock 429s were dogs.  The only reason that engine was ever offered on the street was to homologate it for NASCAR racing.  Ford knew they'd never sell 500 429 powered Torninos a year, but figured they could sell 500 429 powered Mustangs.  The NASCAR rules said 500 production examples of the engine, but not that the engine had to be in the chassis that would be raced.  Ford learned its lesson from the 427 SOHC, which was banned as it was not factory installed in anything.

So the idea was to build 500 429s, and since the engine had tremendous potential they detuned them quite a bit to keep people from being killed on the street.  By '69 the insurance companies had also gotten wise and were charging high premiums for high powered cars, and if the cars were too expensive to insure Ford knew they wouldn't sell enough of them for homologation. 

I knew a guy in college who ran a shop working on Mustangs and he had a Boss 429 that he bought for almost nothing during the gas crunch and raced extensively.  He said stock it was pretty weak, but after talking with the guys who were racing them like Holman and Moody he found out what you had to do to get it to scream.  The potential was there, but the factory configuration was not designed for max power. 

That same guy, no BS, had a Fox body Mustang he put a 351 Cleavland in because people said Cleavlands were junk.  That car ran high 8s in the 1/4 and the engine was nothing terribly special (no stroker, etc.). 

That must have been a REALLY fast Mustang TKO..it would be faster than Bob Glidden;s 340 cid Clevland 1978 Fairmont, tube chassis, lenco 5speed, 2400 lb, World Record Holding Fairmont at 8.49 158mph btw that car was the only Pro Stock ever to go undefeated in a season.
 

I was teaching a course at our Perth facility and looked out to see a GT in the parking lot.  I caught up with the owner and he is quite a car guy with a substantial stable.  The car was an original GT but there are apparently a lot of clones.  With Ford and Holden both closing their doors soon, the old Falcons will likely command some pretty high prices.  A lot of hot rodders over there.  The next day the guy brought in one of his Mustangs - a left-had to right-hand conversion.  The GT got a new radiator the day he brought it in if you're wondering about the large puddle.  Not the most beautiful car but they kind of grow on you!

Raymond_B wrote:

I remember back in the day (like mid 80's) Clevlands were way more popular. Small chamber 4 barrel heads, a big cam and a 4 speed. Knew a guy that had one in a 67 Mustang and it was one of the fastest street race cars in Fort Worth (at least for the Reisinger(sp)/Miller Brewery crowd )

You must be Talking about David Painter... He was know as "The Hand" because he could shift that car so fast....