This is an Edelbrock UR2X tunnel ram. I'm not sure exactly when Edelbrock released this manifold, but it was at least before 1976.
It has the unequal sized runners.
This is the same manifold (not the <span style="text-decoration: underline">actual</span> manifold, just the same model) I ran on the L78 396 I had in my first `67 Chevelle around 1983.
I used a pair of Carter Competition Series 750 AFB's back then, and the swap to this manifold from a 163 with an 800 Holley made a very notable improvement >4K rpm on that little 396.
The current UR2X will eventually make its way onto the 496 in the current Chevelle project. I just had the 163 off of the 496 for cleaning and couldn't resist setting this in place for a quick pic. [img]<<GRAEMLIN_URL>>/grin.gif[/img]
If the manifold makes the same kind of improvement on the 496 that it made on the 396..... [img]<<GRAEMLIN_URL>>/naughty.gif[/img]