[silk]

i am curious about 302 mains and cranks assembled from the factory. were all the cranks large or small journal or both depending on year made? also were all the blocks 4 bolt or 2 bolt or both depending on year made? also one other thing did GM ever cast a block with the same casting number as both a 2 bolt and 4 bolt application. all help is appreciated.

 

[Kyvox]

67=small journal, 2 bolt main. 68=large journal, 2 bolt main. 69=large journal, 4 bolt main.

 

[blown67ss]

Yes some casting #'s cover 2 and 4 bolt mains.

 

[JOE58]

I have an original 1967 Z/28 302 crank. It is a special one year only Z/28 302 crank and not a 283 crank like some people say. It is small journal and the hole in the front of the crank is not tapped for a damper bolt.

 

[silk]

thanks guys. kyvox, would you happen to know when GM changed over to the 4 bolt 69 block from the 68 2 bolt block? my casting date is sept 20th 1968 and built oct 3rd 1968. it was in a early 1969 car. thanks

 

[frankk]

If it's the 386 casting it will be a 4 bolt main. According to MacNeishs book that block was used as early as Jan. 1968.

 

[Kyvox]

Can you post the casting and engine code #'s? Is yours a 4 or 2 bolt?

 

[silk]

well thes numbers have already caused some debate in the past posts i have made but here goes....casting # 3959512 and front pad #'s 19N518336 V1003DZ and casting date # I208. i know, i know, the casting # is not the typical 4 kinds, but no one has been able to say what it is. search for posts from silk under tag team to get the scoop. also the engine is in the car running so i havent been able to drop the pan to see the main caps. that casting code shows as a possible service replacement, so what the chance of that, and would the dealer or factory put the cars vin back on it? note that all info found shows that block to 67 at the latest but mine was casted in late 68 so what gives???

[This message has been edited by silk (edited 01-01-2002).]

 

[Kyvox]

Silk- Could you be mis-reading the casting date? Check to see if it is I 20 "3". Rub a piece of chalk across it to see it better.

 

[JohnZ]

Good definition of the casting date will help figure this out; I show the 9512 block as used for '62-'63 327's, but Flint didn't change their engine plant stamp code from "F" to "V" until July, 1966.

------------------
JohnZ
'69 Z28 Fathom Green

 

[silk]

well i scraped, i rubbed, and i cleaned. the casting date still shows I208. i looked up the same info about it being a 327 62-67 and the heads show for a 1964 327 also so i guess it sounds like a 327 all except for that casting date and it possibly being used as a service replacement block. the balancer is huge also which i have not seen a early 327 with one this big. but who knows? the partial vin on it should translate to something like this 124379N518336, i wonder if that car ever got docomented on camaros.org? and if it did, was it a Z/28?

 

[Kyvox]

Something else to check: On the back of the block, behind the distributor, is there a fitting with a rubber hose running to it? Or even a hole (about 1" diameter) in the block with a plug in it?