396 3935440 block help

[jasonL78]

Thank you very much. I got a complete 68 396 with the chevelle I just bought and I just wanted to know if it was a 2 bolt or 4 bolt main without moving the oil pan. Thanks again

[bertfam]

No problems Jason. So which one did it turn out to be? Two or Four?

Ed

[COPO_Anders]

How do you explain the fact that I have two 4-bolt main blocks with the small "oil holes" ?
This pic is from my late -69 4-bolt #512 block.

[COPO_Anders]

And this one is from my 1990 marine 454 4-bolt #286 block.

[jasonL78]

Mine ended up having the small hole so I guess it must be a 2 bolt main block. It does have the 2 step oil pan on it. Would the 325hp motor have a windage tray! I will double check it when I get time. I have been looking for a April or May 440 4 bolt block for my 68 L78 nova. The one I just got is a E-18-8 block.The motor I have in the nova now is a 2 bolt main out of a 68 4 speed 350hp chevelle. I want to build a correct L78 motor for my nova in the future. If this block I have would have worked then I was going to use it. I thought the only difference might be the main caps. So I guess the search continues and the motor will most likely go into the 67 chevelle.

Jason

[bertfam]

[ QUOTE ]
How do you explain the fact that I have two 4-bolt main blocks with the small "oil holes"?

[/ QUOTE ]

I can't

Ed

[3macs1]

There was a lot of discussion on this on the technical form
See pg 2 1970 3963512 block strange one.
These may be the pictures that we are looking for.

[nuch_ss396]

[ QUOTE ]
Mine ended up having the small hole so I guess it must be a 2 bolt main block. It does have the 2 step oil pan on it. Would the 325hp motor have a windage tray! I will double check it when I get time. I have been looking for a April or May 440 4 bolt block for my 68 L78 nova. The one I just got is a E-18-8 block.The motor I have in the nova now is a 2 bolt main out of a 68 4 speed 350hp chevelle. I want to build a correct L78 motor for my nova in the future. If this block I have would have worked then I was going to use it. I thought the only difference might be the main caps. So I guess the search continues and the motor will most likely go into the 67 chevelle.

Jason

[/ QUOTE ]

Jason,

The Camaro, Nova, and Chevelle didn't get a windage tray on
the Mark IV engines. I believe this was reserved only for
the SHP versions of the Corvette. This would include the L/71 & L-88 & ZL-1.
I don't believe any oval port engines got the windage tray either.
I'm also not sure about the L/72 optioned full sized cars.
It may be possible they had a windage tray. I know some
members here are knowledgeable about the full sized cars.
Perhaps they can chime-in on this. One other bit of
windage tray trivia for you. I had asked a few ZL-1 Camaro
owners about whether or not their 427's came from the factory
with the windage tray provision. Some reported no. Others
said thay the oil pan baffles had to be removed to fit the
windage tray in the Camaro oil pan. I don't think there
was a conclusive answer given. However, since L/78 Camaros
did not come with the windage tray provision, I'd have to think
that the windage tray on the ZL-1 was an oddity.

The two-step oil pan had nothing to do with the windage tray
provision. That was the pan used on full size cars and
possibly others. I suspect that the Camaro & Nova were the
only big blocks to receive the oil pan they did, due to
subframe and/or steering clearance. Possibly the Chevelle
fits into this category as well. I know others here have
that information.

As another member suggested, this topic of 4-bolt blocks
without the external oil cooling provision was discussed a
short time ago. My research has indicated that at the
time of manufacture ( machining for 4-bolt main caps ), the
Tonawanda facility would have had no idea of the application
that particular big block was going into and as such it would
have also been machined for the external oil cooling provision.
Those two machining operations were done as a
set.

Lastly, I had asked a number of very knowledgeable big block
current & ex-racers ( Mark IV's ) about this 4-bolt main
block w/o the external oil cooling provision and none of them
had ever seen a 4-bolt main block ( built that way by
Tonawanda ) without also having the external oil cooling
provision present. As one NCRS member suggested to me,
GM sold 4-bolt main cap & bolt sets over the parts counter
for many years. Undoubtedly, many of those found there
way onto two-bolt main blocks.

Steve