apples and oranges
The C8,C9 and D0 passenger car heads were a better head for that application, namely providing enough torque with reasonable (by the standard of the day) fuel economy to move those big boats around. The CJ head was a race head. If you put a CJ head on a 429 Thunderjet in a TBird and made no other changes it would not perform as well as the original passenger car head.
. I pulled this motor (and C6) out of a 1970 Galaxy. As to the transmission, I had to install a different detent rod as the C6 was a column shift and the Grande utilizes a floor shift. Otherwise, the C6 is essentially the same..As Tommy stated, the comparison between Mustang 429 heads and more "run of the mill" 429 heads comes down to the fact that the Mustangs all used the 429CJ/SCJ heads.
That does not mean the "regular" heads are not good as they can make some serious power and TORQUE. These early heads can be identified by the casting numbers C8SZ-B, C8VE-E and D0VE-C. These heads have a combustion chamber volume of 75.8 cc and utilize Intake Valve of 2.08" and exhaust valves of 1.66". These heads are considered much better (for performance) than the later 72-78 heads as the later heads have much larger combustion chambers.
The 429CJ/429SCJ/Police heads have a combustion chamber of 73.5 cc with 2.24"/1.725" valves. These heads also come with adjustable rocker arms.
The 68-70 429 blocks are essentially the same except for the fact that the 429SCJ blocks for 1970 and 1971 had four bolt mains. The 1971 CJ block also had four bolt main.
My $.02... I have a 1970 passenger car engine in "Ice" (my '73 Grande) and I am making @ 500 horsepower with gobs of torque with a relatively mild build. Those early 429/460 engines have been purported to make much, much more
Hope this helps
BT
Just as a side note 429 SCJ and CJ heads are the same thing with The police Interceptors been different again. As in smaller ports and valves..As Tommy stated, the comparison between Mustang 429 heads and more "run of the mill" 429 heads comes down to the fact that the Mustangs all used the 429CJ/SCJ heads.
That does not mean the "regular" heads are not good as they can make some serious power and TORQUE. These early heads can be identified by the casting numbers C8SZ-B, C8VE-E and D0VE-C. These heads have a combustion chamber volume of 75.8 cc and utilize Intake Valve of 2.08" and exhaust valves of 1.66". These heads are considered much better (for performance) than the later 72-78 heads as the later heads have much larger combustion chambers.
The 429CJ/429SCJ/Police heads have a combustion chamber of 73.5 cc with 2.24"/1.725" valves. These heads also come with adjustable rocker arms.
The 68-70 429 blocks are essentially the same except for the fact that the 429SCJ blocks for 1970 and 1971 had four bolt mains. The 1971 CJ block also had four bolt main.
My $.02... I have a 1970 passenger car engine in "Ice" (my '73 Grande) and I am making @ 500 horsepower with gobs of torque with a relatively mild build. Those early 429/460 engines have been purported to make much, much more
Hope this helps
BT
