Boss 429
Boss 429
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Joined: Dec 2003
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From: iowa
the biggest thing is the fact it has hemi style aluminum heads, there are many small differences, but that is the glaring difference in them. I think that is what you are asking is what makes them different than any other 429 ford
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Joined: Dec 2003
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From: Eastern Ohio
The main thing was the heads... altho there were some differences in the blocks, etc, between them and production 429's.... You think the heads look different, wait til you see the rocker arms LOL.... One of these days we will get around to putting the 70 Boss Mustang we have in the garage back together
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Joined: Dec 2003
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From: Honkytonkville
The block itself had a shorter deck height for increased compression along with 4 bolt mains....correct? I know there were individual blocks cast solely for the purpose of use in this engine. I found a site that listed the various differences, which also included a high rise factory aluminum intake. It also said that no head gaskets were used, but instead o rings around all of the passages and cylinders....Is this true, because it doesn't sound logical to me.
Scott
Scott
Last edited by scottie2hottie; Oct 9, 2004 at 01:47 PM.
Laughing Gas
Joined: Jun 2003
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From: Chino, California
The Boss 429 had crescent shaped combustion chambers. hence the nickname 'blue crescent' and 'semi-hemi'. They didn't qualify as hemi-heads. The other factor was also the solid valve train in the hotter rigs. (yes, some cam with hydraulics)
Heads were aluminum with poly-angle valves, fed by a 735 cfm Holley 4bbl on an aluminum high-rise intake manifold.
The heads had huge oval ports and awesome valve diameters. It was built for rpm's.
The car (Mustang's) had the battery in the truck, and trick suspension. Cool air hood scoops, etc.
Heads were aluminum with poly-angle valves, fed by a 735 cfm Holley 4bbl on an aluminum high-rise intake manifold.
The heads had huge oval ports and awesome valve diameters. It was built for rpm's.
The car (Mustang's) had the battery in the truck, and trick suspension. Cool air hood scoops, etc.
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Joined: Dec 2003
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From: iowa
the blocks also have a different oil return passage on them, and yes the heads are oringed, and no you can't just bolt a set of boss heads on a standard block without some major modifications, they also had a steel crank, and factory forged pistons, and a slightly revised oiling system but not sure exactly what was different on that part.
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Joined: Oct 2004
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From: new brunswick
rumor has it that the designers at ford were aable to get 657hp @ 7800rpms(wow) and corperate brass made them "detune" the for street use and put a smaller cam, smaller carb and redesign the heads from a full on hemi design to the cresent style. the choked out motor could only muster 375hp and turned into the motor that could have been instead of the motor that was.the older 428fe mustang would blow the doors off any boss429(sorry) and it should never been able to and we won't talk about what a 427fe powered farlane would do to it. i believe ford had the best motor they ever built(comparable to the 426hemi) but in the end were scared to unleash it on the public-too bad would have been proud to have the baddest production engine of all time on our side.agood book for reference is called fastfords-good reading.
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Joined: May 2002
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From: Broken Arrow, OK
The Boss also had 4 bolt mains. How many caps got 4 bolts depended on what the engine was to be used for. Some had them on all 5 bearings, some on 4 and maybe some on 3. One year of the Boss heads will bolt on to a regular block and work because the O-ring grooves are in the head instead of the block. 69 was one way and 70 was the other, don't remember which was which. Some of the Boss heads were a full hemi, but it cost them a lot of low end torque. The chambers were filled on two sides to help the low end, hence the crescent nomenclature. They were detuned rediculously, but tons of power is only a cam swap away. There is a guy that comes to the Mid American Shelby and Ford Performance Meet here every year with a Boss 429 that runs 10's. All he has done (so he says) to the engine is add the factory dual quad intake, change cams and add headers.
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