question about 360 heads

[70Swinger]

hey, i know someone who is selling a pari for 74-75 360 heads. could they be X, J, or O heads?

Thnx Adam

 

[rumblefish360]

Yes. Look for the letter next to the spark plug holes. Also, the numbers off the head. In basic form, OOTB so to speak, they perform about equal in street trim, ported or not. It's when your looking to push out some power there abit different in porting technics and amount of porting needed to have them perform equal.
All the letter heads are about the same. Valves not withstanding. (Apples to apples equal apples.)

 

[Mark Nixon]

hey, i know someone who is selling a pari for 74-75 360 heads. could they be X, J, or O heads?

Thnx Adam

No, they wouldn't be, not originally, anyway.
'X' heads were used from '68 through early 1970, but some were used in later '71 when Chrysler knew they'd probably be phasing out the 2.02 intake valve and wanted to clear backstock from the shelves.
The 'J' heads were used '70 through '72 and had either 2.02 or 1.88 intake valves.
The 1.88 valved 'J' heads were used on '71-'72 360 and '72 340s.

The 'O' heads, like the 'Z' and 'U' head were used in the latter part of the 1970 Model year and were USUALLY 340 2.02 valved heads, but a few made it onto the itroduction of the 360 in the late 1970 model year, in the form of 1.88 valved castings.

Yes, there is an application that used a 360 in 1970!!

Mark.

 

[rumblefish360]

Yes, there is an application that used a 360 in 1970!!

Do tell.
They still could be a letter head. Not correct for the year. Thats why I said to get the numbers off the head.