Kinda weird

[Hossbee]

Tore down my 400. The casting date on block is 8-17-75. Took valve covers off an one head is a 452 and the other is a 975. Is this common. I know the 452 were started in 76 and the 975 was 74-75 I believe. Don't know history of motor. It is stock bore size. I never heard the engine run. Just got it. Didn't want to put them back on after rebuild it they wouldn't work together.

 

[72Satellite440]

Read this article-seems that there are very few differences-

http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/index.html

 

[Hossbee]

Cool. Thanks for the link.

 

[FatJack]

Great link, gonna have to save that!!