69 DZ Blocks

[HOT3O2]

Could someone tell me why Chevy used 4 different blocks for the 69 DZ 302 through out it's production. Was there any changes on the blocks besides the casting numbers?  Thanks

[68Zproject]

I don't know specifically what the differences were.  If you have a Colvin's By the Numbers, he lists what some of the changes were.  Most were very minor.  Also, the casting numbers could be used for other engine sizes as well.  All Chevy did was change the crank and rods to make 302's, 327's and 350's.

[william]

Sucessful manufacturing has always required continuous improvement. Starting in '67 most cars carried a 5 year 50,000 mile power train warranty. Field failures were analyzed and appropriate changes made. That's why casting numbers sometimes changed. Improvements such as 4-bolt main cylinder blocks and screw-in rocker arm studs were part of the process.

Some of the back-door factory hot-rods such as Hemis did not have the traditional warranty for obvious reasons. Chevy fully covered all of their cars and I'm sure they regretted it.

[HOT3O2]

I see there were 3 regularly used blocks in 69: 3932386, 3956618, 3970010. Where did the 3932388 block come into play? Was this a left over block Chevy was trying to get rid of ? How rare is it to see one of these (388) blocks in a 69 Z28?

[tmodel66]

According to CRG: "The 3932388 block is sometimes noted as being 'rare', but it actually was commonly used in mid-69 production."

[sam]

Again, DZ is not a block just a suffix code.

[1968RSZ28]

How rare is it to see one of these (388) blocks in a 69 Z28?

See Kurt's reply (#5) in this thread...  http://www.camaros.org/forum/index.php?topic=3267.0

Paul

[HOT3O2]

Thanks for pointing me in the right direction Paul,  That cleared things up for me.

[HOT3O2]

In reading Jerry's New book (4th Edition) he states his research shows the 388 block was used mid year between Feb. 69 thru May 69. and only in 302's. And a range of 3 to 6 weeks from casting to assembly. Has any one seen a 388 block use on any early (68) built DZ motors?

[crobjones2]

In reading Jerry's New book (4th Edition) he states his research shows the 388 block was used mid year between Feb. 69 thru May 69. and only in 302's.

Interesting, I have a 388 block May 69 cast but in a 350

[HOT3O2]

That is interesting Chris. Jerry's book did mention that some of the early 350's used the 388 block. What is the cast and assembly dates on your block?

[JKZ27]

My late November (68) built L48 is a 388 block. I also have a L48 block from a 69 full size wagon that is a 388 2 bolt main.

John

[crobjones2]

That is interesting Chris. Jerry's book did mention that some of the early 350's used the 388 block. What is the cast and assembly dates on your block?

E20 with a build of 0526

[HOT3O2]

Thanks for the reply's Chris and John. I have a 12B RS Z28 with a 388 block. Casting date(K308) and a build date(V1203DZ). I thought it was a little early to have that block in a Z but who know how they put thing together back then. Grab a block, build it, and not check numbers? I guess anything was possible.

[sam]

 They probably grabbed any 4 bolt block available for the build. Probably not to concerned about a 388,386, 010 or whatever in those days. Get the car built and sold.