1969 Z28 Cross Ram Help???

[Als 70 L78 Nova]

I picked up around 70 intakes and 50 carbs today and one was a cross ram I thought. The casting numbers are right and they look to be original. Here is the problem. The top does not match up to the bottom. The top is a 3941130 with a casting date of 8-20-69 and 3/8" holes. The bottom is 3941126 with a casting date of 11-25-68 and 1/4" holes. What gives? Any help would be appreciated.
Al in Maine

[DW31S]

Is it the way you have the top positioned, or does it NOT match the bottom? I'm wondering if the earlier of the two is/was cast during the developmental stages of production. Try Jerry MacNeish, or one of his books. I know John Hooper's books covered crossrams, but I do not have any contact info. for him. Last I heard he was in DE and had a new ZL1 stolen from a new car dealership.

[Als 70 L78 Nova]

The holes do not line up regardless of how it is turned and the hole sizes are different.

[Kurt S]

http://www.camaros.net/forums/showthread.php?t=273337

Why not wait to see the answers from one forum first?

[Als 70 L78 Nova]

I am a little surprised that posting a question on two forums would bother you. Just saying.

[67 Nova Boy]

They might be the reproductions maybe? I have seen the tops on eBay that the

seller says they won't fit their bottoms and seem to be GM or repo's. The top

may fit the bottom of an Offenhauser.

Dave
67 Nova Boy

[Kurt S]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Als 70 L78 Nova</div><div class="ubbcode-body">I am a little surprised that posting a question on two forums would bother you. Just saying. </div></div>
I often have to dig out research info and type up a reply.
I get frustrated when I find out there's already an answer posted in another forum. It's a waste of my time.

[Als 70 L78 Nova]

My apologies to you.

[Lynn]

I had a GM cross ram top years ago, and can say with certainty that it did not fit the Offy or the Edelbrock bottom.

So.... are you saying the reproduction cross ram isn't the same bolt pattern as the GM? That would seem a major goof.

Also, don't the repros all have the same casting date? Anyone know that date?

[iluv69s]

First of all, the repo tops fit the GM bottoms. Second, the early prototype intakes all bolt up with the later tops and bottoms. The changes were minor once they started the 'production' intakes.

The bottom does not look GM to me off the top of my head. I see no bosses for the oil sheild mounting points that the early units had. These bosses were on all the intakes even though they cancelled the oil sheild. The top looks like a repo also. It is difficult from pics because the repos are pretty good. If you can post some closeups of the edges of the intake top and also the mating surface where the top mates to the bottom, I can tell you definitively. The machining marks are a giveaway between the new repros and the originals.
I can pull out one of my original intakes to compare. I also have an offy intake that ill look at to compare. I would bet that you have an Offy base..and a repo top.