CLASS RACER FORUM - 1969-1970 Boss 429's

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1969-1970 Boss 429's

Here's a photo of Mickey Thompson's Boss 429 Mustang, with driver Butch Leal...In the past I've seen these motors in different types of cars in several different classes...but were these motors competitive...post any photos & stories facts or stats that you might have.

http://farm4.static.flickr.com/3584/...68ffc439_b.jpg

Re: 1969-1970 Boss 429's

Though a beautiful car,,,,,,,
The Boss 429 'Shotgun' did not arrive without it's problems.

The 1969 Boss 429's (first ones out) were 'slugs'.

Engine problems;
Valves too big
Cylinder head port passages 'monster size' worked against the flow
Weak valve springs
Hydraulic lifters
Connecting-rods too heavy
Holley 735 CFM carburetor undersized

* The engines could not rev above 4800 RPM's

Despite claims of 13.50's @ 107 MPH,,,,
Car Life Magazine tested one with 3.91 gears, in July 1969.

Performance Results; 14.09 @ 102.85 MPH.

1969 NHRA Classes; C/S or SS/F.

Re: 1969-1970 Boss 429's

Here are some drag tests from back in day...

1969 Mustang Boss 429 (HPC)

429ci/375hp, 4spd, 3.91, 0-60 - n/a, 1/4 mile - 13.34 @ 107mph

1970 Mustang Boss 429 (SS)

429ci/375hp, 4spd, 3.91, 0-60 - n/a, 1/4 mile - 13.64 @ 104.65mph

http://roadtests.tripod.com/index.html

http://image.mustangandfords.com/f/f...on_factory.jpg

Re: 1969-1970 Boss 429's

There is a Blue one that has lived it's life right here in my home town. It has had several owners and the current owner had a resto done (by Mashburn Mustangs in Little Rock.....???) on it in the late 90's. 98-99-2000...I did the engine and it was a real challenge to bring it back from "all blowed up"... I worked 3 years on it. most of the time was searching for the correct parts. I had to weld the lifter galley back together and put in lifter bore bushings. Never did locate a couple of rocker stands. Had to build them on a mill myself. It is a cool ride now. Used at car shows and an occasional trip down state line. There was a Maroon one that was a twin sister to the blue one. Both of them hit town at the same dealership. McClarty Ford. I think the engine in the Maroon one was replaces with a Boss 302 and the car drove off into the sunset. The Boss 429 ended up in a V-drive boat for a while and the last owner sold it to either Jim Kuntz or Keith Kraft. I'm not sure which Ark Ford guy got it since the owner isn't with us anymore. I see the Blue Boss's former ( I think #2) owners Ex wife post on face book alot. I've even ask her if she remembers the car. I bet there are more 429 Boss stories like that going around.

Re: 1969-1970 Boss 429's