Any truth to this 396/402 update?
 

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Well I know this to be somewhat true from experience. Buddy of mine had a 375hp 396 and he blew the motor. Most of his parts dealings were through the dealer. When he opened up the motor he found that it was .030 over. He went to the dealer thinking he could get some warrenty relief. The dealer showed him a GM letter that explained why the motor was a &quot;402&quot; and that there was a series of blocks that were inadvertantly bored .030. also interesting is the fact that the pistons were TRW. This was in late 69. He bought the car off the lot in 68 after getting home from Viet Nam. </div></div>

Re: Any truth to this 396/402 update?
 

I don't think this was that unusual accross manufacturer's. I have had some Mopar motors which were the same way.

Re: Any truth to this 396/402 update?
 

He's claiming there was a mistake.

Re: Any truth to this 396/402 update?
 

I remember at some point that seemed to have happened. I had a 69 dusk blue 350 hp 396 with ac that when I went to have it rebuilt the machine shop guy told me it was already 30 over and thought it had never been rebuilt. Ten the 70 SS 396 Chevelle was actually a 402&quot;.

Re: Any truth to this 396/402 update?
 

What model year was the car in question?

Re: Any truth to this 396/402 update?
 

I think you're missing the point.

He's claiming that the bored-out 396 was initially a mistake and suggesting that &quot;The dealer showed him a GM letter that explained why the motor was a &quot;402&quot; and that there was a series of blocks that were inadvertantly bored .030. also interesting is the fact that the pistons were TRW.&quot;

I've never heard this and believe it to be wrong. The only thing I've heard ever was that all 396s in 1970 were 402s and that was a running change, most likely for emissions reasons.

I was hoping someone here would know for sure.

Re: Any truth to this 396/402 update?
 

If the 69 Camaro was a late production car (Fall of 69) the engine would have been a 402.

Didn't the 1970 modelyear 396 engines became 402, and for Tonawanda all production was for 1970 even if the Camaro was called a 69.

That they still were labeled 396, that's a different story.


Jan

Re: Any truth to this 396/402 update?
 

There's a technical bulletin that talks about the late `69 396's as being .030 oversize.

http://i36.photobucket.com/albums/e4...ulletin009.jpg

Re: Any truth to this 396/402 update?
 

i thought i remembered that they were green blocks that were machined too soon and had to be rebored .30 over.

Re: Any truth to this 396/402 update?
 

What I was told in order to meet the new emmsion problems the cubes would have to increase in order to have the same HP.

The 283=307 the 327 = 350 the 396= 402 and the 427= 454

All motors were increased in size.