69 z28's had 302's and were 4 bolt mains,casting #-3970010, cubic inch-302, year-69, main caps-4, model-Z-28 Camaro

 

The 67 and 68 Z28 used a 4-bolt main cap as well.

 

The 67-68 "MO" blocks were small crank TWO bolt main
only the 69 "DZ" blocks were 4 bolt (0010) castings with the large cranks I have seen and owned both types of blocks, there werent any early casting 283/327 blocks made with four bolt mains it wasen't until the 350 block was used for the 302 conversions in 69 that the 4 bolt was used .. even though they had a 350 as early as 67 it was not used in the 302 form until late 68 as a 69 model in the Z/28.

 

I am sure that I read that even the old blocks were 4-bolt mains as well?

 

The old "MO" blocks were based on the 327 block which were only offered in two bolt configureation they used the small journal crankshaft, there were No 4 bolt 327s, the 69 was based on the new "350" block which incorperated the four bolt mains and a large journal crankshaft on the 3970010 casting block , there may have been some early "One Offs" and test mules with the 350 block (possibly the transmission am race cars) but the production models were two bolt until 69 ...im reasonably sure of that as I have seen examples of both the MO and DZ blocks ..

 

What about the MP blocks, were those 2-bolts also?

 

Im not fermilliar with that listing... the "MO" and "DZ" markings were the only Z/28 listings for the 67-69 model years that im aware of do you have a casting # if it's a 327 it would be a two bolt, most engines pre 1966 were all 2 bolt castings I believe the first 4 bolt was the 3970010 casting in the 67 SS camaros 350ci everything before that was 2 bolt unless it was a pre production model ...I COULD be mistaken but thats the way I remember them being and I worked on alot of engines over the years ..

 

musclecarclub.com?

 

just google penske sunoco 69 camaro or transmission am racing and start educating yourself on old school factory transmission am racing

 

Sorry to disagree with you mortis. 69 (DZ) blocks were 4 bolt mains not 2. Speaking as a previous owner of an X33 Z28