1969 Z28 Block Casting # question
 

Hi,
I have a 1969 Daytona Yellow/Black Z28 DZ 302. My question is the block casting # is 3932388. Now I looked this # up and it gives me two motors for the same number, 302 Z28, and a 350 used in other cars. Is this correct? How would I know which is which? Do I have a correct motor car? Please let me know if you have any insight. Thanks. Eric

Re: 1969 Z28 Block Casting # question
 

Yes, that's because they are the same block. The 302 was a destrocked 350.
You have to measure the stroke.
Probably, people have a tendancy to keep 69's original as possible. They're worth more.

Re: 1969 Z28 Block Casting # question
 

if you can see the crankshaft flange where the flywheel bolts to, the shape will tell you which crank it has. the 302 had an almost round flange
also if you can take the pan off you can check the casting #
heres a site that has a list of the casting #'s
http://www.mortec.com/cranks.htm


Wade

Re: 1969 Z28 Block Casting # question
 

ecross4 welcome to the board... pics of your Z??? :D

If you want to verify originality of the motor, look at the pad on the block right under the alternator in front of the passenger head. It will have #s that should match #s in your VIN, and will have the engine code on it, I think 69 302s were DZ.

Since these cars are so valuable, sometimes guys will take a non original block, machine down the block, restamp the block to match the info for the car. Then you have to look at casting #s and dates. If your car was built in April of 69, obviously it wouldn't have a block or heads with dates after 4-69. But then you get guys that grind down the casting dates/numbers and make new ones using epoxy loaded with iron fillings. This started years ago with Corvettes/Hemis, and now that some Fbods are selling for huge bucks, wouldn't doubt that it's happening on them too. So in the end, I guess you'd have to have an expert verify the originality of your engine and issue you a certificate of authenticity. Which could also be counterfeited. lols.

Not something I have to worry about on my car, but I wouldn't mind having your problem. ;)

Re: 1969 Z28 Block Casting # question
 

I believe there were a total of four different block casting numbers for the 69 year run, 388 was one of them. The Jerry macneish Z/28 and SS396 fact book is the best book for any Z28 or big block Camaro owner. I would highly suggest buying a copy, anything you need to know about your car is in that book.

Re: 1969 Z28 Block Casting # question
 

I have the MacNeish book in front of me and have been through it about fifty times. The only true way to tell if your motor is a number's matching unit is if the last six numbers of the vin are stamped on it. These numbers would either be located on the front pad (passenger side) or on the back of the motor, drivers side behind the oil filter. The stamping will be on a rough cast surface and it is hard to find depending on the stamp. I have a DZ motor in my garage and haven't been able to find a vin on it at all. I really need to clean it up and look closer. If it matches the Z I bought, it would probably double the value. Hope you have good luck.

Dave

By the way my car is a Los Angeles car, Daytona yellow top and bottom. Std. Interior. Real clean, but need to verify that DZ and get it back in. Currently has 454 crate (425 HP with a TH400). My muncie does not match.

Re: 1969 Z28 Block Casting # question
 

350ci 300hp

Re: 1969 Z28 Block Casting # question
 

I think it was Dec. 68 that the Vin was moved from the front pad to the rough casting by the oil filter. From my personal experience the numbers in the casting were stamped really light and hard to read if you can read them at all. If the Date matches your build and the cast number is correct then it is considered numbers matching. You can also buy stamp kits in Hemmings with the correct numeric and letter character and if done correctly even a seasoned Camaro veteran couldnt tell them from original.

Re: 1969 Z28 Block Casting # question
 

but what i think he wants to know is if the motor has been built up at all, and the ways to tell are to measure you're stroke, and that can be done by poppin a head off, or you can check the crank flange to see if it's a destroked crank or a standard 350 crank, which requires you to get under her and look at the rear of the crank...

but nice thing is visibly it's a numbers matching motor, internally, it can be made to original spec again, just put the destroked crank in and whatnot, so you want the torque leave it as is, you want the originality destroke her, simple really

Re: 1969 Z28 Block Casting # question
 

This was kind of my point in the beginning. There is no way to know what's been done to a 30 year old motor without taking it apart. Could be a 383ci for all we know.

Re: 1969 Z28 Block Casting # question
 

A 383 would be easily identified by the externally ballanced 400 balancer.
Yes you are correct though, I personally would put the 350 crank back in it for the added performance. Otherwise you just have an overbored 283. The DZ302 may have been the hot ticket for its day but by todays standards it a dog. I personally dont think it hurts the value of the car to do the 350 crank, it makes the car more enjoyable and thats what its all about.

just my .02

Re: 1969 Z28 Block Casting # question
 

if you can get under the oil pan, the crank should be an 1178 casting. the block could be a 386,388 or 010 in 1969 302.