Difference between 429 Cobra & 429 Boss
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From: Denison, Tx
Difference between 429 Cobra & 429 Boss
I would like to know the difference between a 429 Cobra and a 429 Boss, and more importantly, can I add 429 Boss Heads to a 429 Cobra block and achieve the same results (would I have a 429 Boss) ?
I'm sure it's not that easy, and there may very well be big differences between a Cobra and Boss block (more than just the Boss heads).
Please advise -
I was looking at the 429 Cobra engine listed on ebay at the link below, and was wondering if adding Boss heads would be a good way to go.
Thanks for any background.
Mike
I'm sure it's not that easy, and there may very well be big differences between a Cobra and Boss block (more than just the Boss heads).
Please advise -
I was looking at the 429 Cobra engine listed on ebay at the link below, and was wondering if adding Boss heads would be a good way to go.
Thanks for any background.
Mike
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Junior User
Joined: Jul 2001
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From: Denison, Tx
Here's the link
Sorry, forgot the link:
429 Cobra engine on Ebay -
Personally, I didn't know Ford produced the 429 Cobra in 1969.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=2478459578
Thanks
429 Cobra engine on Ebay -
Personally, I didn't know Ford produced the 429 Cobra in 1969.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=2478459578
Thanks
Posting Guru
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From: Everett, Wa
IMO i would stay away from that engine unless you can go see it in person before buying. All 429 blocks in 69 are the same except the Boss which that engine is not. There where only a few hunderd ever built.
If you want an engine you can be sure of build one yourself. I would not go with boss heads unless you are doing it for nastalgia reason, i.e. putting the engine in a Mustang or Courgar. Go to a junk yard and find a 429/460, you should be able to pick it up for around $150. Rebuild it, slap on the new SCJ heads and you will have better performance than the Boss anyway.
Just my IMO.
If you want an engine you can be sure of build one yourself. I would not go with boss heads unless you are doing it for nastalgia reason, i.e. putting the engine in a Mustang or Courgar. Go to a junk yard and find a 429/460, you should be able to pick it up for around $150. Rebuild it, slap on the new SCJ heads and you will have better performance than the Boss anyway.
Just my IMO.
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From: iowa
I would go with Ford scj heads as well. They will outperform the the boss. The thing with the 429 boss was that it was a top end screamer. Thats not great for the street like it is for the track. The scj heads are advertised as 40-50hp over cj heads.
Last edited by fordeverpower; May 21, 2004 at 12:26 PM.
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From: Copley, OH
The Boss heads are scarce as hens' teeth and grossly expensive. They may still be available new from AR Inc. at a price. They make almost no power at low RPMs on a 429 but massive power at high revs; they are a bit more flexible on a 460 but they are still not what most people need or want on a truck. Basically Ford built them to homologate the heads for NASCAR racing, they really don't belong on the street. Stick with the SCJ heads. John Kaase had a hand in their design; he knows big-block Fords.
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From: iowa
the lesson here is that scj heads are better but either one on a 429 will be no good for the street or in a truck. If you get a mild 429 for a truck or car you will be alright.
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From: Harrisburg, SD
the boss head is a completely different head than the scj or cj, its fords version of the "hemi" and you cant bolt them onto a regular 429/460 block. I have held 429 scj and cj heads in my hands and ran them on the flow bench, the scj heads only flowed about 10cfm more. thats enough to support another 20ish horsepower.
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From: Everett, Wa
Sorry v8xploder but you infomation is incorrect. The true hemi Ford built back when was the 427 sohc. The 429 Boss is a OHV engine and the heads bolt up to any 429/460 block. The Boss heads are not even a true hemi head but a quench-hemi. The only mod needed to run these heads is to machine reliefs for the exhaust pushrods.
Also the new SCJ heads out flow the CJ head by an average of 20cfm and at some lifts by better than 50cfm. Of course do we need this type of flow in our trucks.
Also the new SCJ heads out flow the CJ head by an average of 20cfm and at some lifts by better than 50cfm. Of course do we need this type of flow in our trucks.
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From: iowa
the Kaase super cobra jet heads
Revised valve angles and a more central valve location reduces cylinder wall shrouding and improves flow to 345cfm intake and 225cfm on the exhaust. Exhaust flows into redisgned 72cc combustion chambers for a 40-50 hp increase over current cj heads.
429-460 application is $2060 complete pair.
Revised valve angles and a more central valve location reduces cylinder wall shrouding and improves flow to 345cfm intake and 225cfm on the exhaust. Exhaust flows into redisgned 72cc combustion chambers for a 40-50 hp increase over current cj heads.
429-460 application is $2060 complete pair.
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From: Harrisburg, SD
well yes and no, the boss was fords Semi-hemi, because of the hemispherical combustion chambers, the ohv has nothing to do with it. the valves are located in a crescant on the top of the chamber. The sohc 427 is not a hemi.
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From: Everett, Wa
The 427 SOHC head is the only true hemispherical combustion chamber that Ford made that saw any large street use, at least compared to the Boss 429.
I will corrct myself though. The boss head came in 2 different configuration. One head is a true hemi head and from every thing I can find was used for competition only. The other head is not a true hemi combustion chamber, it was squared off to provide a small quench area. This was also used in competition but is also the head that was used for the Street Boss.
Of course the real problem here is that only a few hundred of these engines ever saw the street. The rest where only available to racers. In many ways this engines are almost all 1 off's considering the number of changes that were made to them in the couple of years they where made.
If someone really wants these heads though you can still buy them for @ 6 grand for a pair, bare.
I will corrct myself though. The boss head came in 2 different configuration. One head is a true hemi head and from every thing I can find was used for competition only. The other head is not a true hemi combustion chamber, it was squared off to provide a small quench area. This was also used in competition but is also the head that was used for the Street Boss.
Of course the real problem here is that only a few hundred of these engines ever saw the street. The rest where only available to racers. In many ways this engines are almost all 1 off's considering the number of changes that were made to them in the couple of years they where made.
If someone really wants these heads though you can still buy them for @ 6 grand for a pair, bare.
Last edited by tmyers; May 24, 2004 at 11:02 PM.
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From: Everett, Wa
SR where are you getting this info I would like to know. The 427 SOHC was available from Ford in 65-68. Many found there way in to street machines and even more in racing, many more that the boss 429. In fact I know of 10 in my area but the guy won't sell them.
The standard 427 head was a OHV, wedge design and came in many different flavors. The SOHC came with only 1 head, a hemi head. I'm quoting here "Although the Boss 429 is often referred to as the "Hemi", the SOHC is the only production engine made by Ford that had a true hemispherical combustion chamber." It that is not a hemi I don't know what is.
There are @ 12 differnt head designs including the SOHC head that will bolt to an FE block. There might be some interference with the larger valves of the bigger engines to the smaller FE engines.
Oh by the way I just saw a Boss 429 for sale, Nascar version with alot of history for $23,500. Will see if they get it. I would love to buy that for my 56 but I have heard that there is available or will be new 427 SOHC.
The standard 427 head was a OHV, wedge design and came in many different flavors. The SOHC came with only 1 head, a hemi head. I'm quoting here "Although the Boss 429 is often referred to as the "Hemi", the SOHC is the only production engine made by Ford that had a true hemispherical combustion chamber." It that is not a hemi I don't know what is.
There are @ 12 differnt head designs including the SOHC head that will bolt to an FE block. There might be some interference with the larger valves of the bigger engines to the smaller FE engines.
Oh by the way I just saw a Boss 429 for sale, Nascar version with alot of history for $23,500. Will see if they get it. I would love to buy that for my 56 but I have heard that there is available or will be new 427 SOHC.
Last edited by tmyers; May 25, 2004 at 02:55 PM.
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All 427 SOHCs hemis. All Boss 429s were semi-hemis.
