Yeah i did it a long time ago. Was having trouble getting over the mountain to my old job.So you have a 4 barrel Edelbrock carb on an adapter, on the stock 260 2 barrel manifold? All 260 had factory Dualjet 2 barrel carbs, so if it is 4 barrel manifold, someone put it on.
The original adapter config is below. But that's the new replacement black manifold base gasket under it in the picture.
The old gasket.. being a bare surface under the Edelbrock 600 ... was getting pretty rough and certainly causing flow disruption.
I got away with this because the manifold under it had reasonable representation.. Bolted the 4bbl adapter and base gasket right to the manifold.
I think I discarded it , but I could see witness marks from the old four vapor jets were embedded into it. It was pretty rough.
This setup would be revisited under tighter scrutiny last weekend as below.
That steel plate weighs a couple pounds and is almost 1/4 " thick.
Old setup vs. new compared below. Now the 4bbl has a nice stainless surface . And no distorted adapter wall.
Measurable or not, I should be getting some gains in there.
Basically, instead of mounting the adapter to the manifold, I brought the manifold base to accept the 4bbl adapter.
From here, I took the MrGasket 1932 with it's gasket, positioned it on the assembly above, and tapped it with a rubber mallet.
That left me where to countersink the 4 chrome hex heads and cut the gasket holes.
Now I mount the carb and adapter to the four corners of the plate.
This is the first time I have had a decent idle since her reawakening. And vacuum guage has me at 18-20 in/Hg. It sounds great and working good.
And that's how I get a 4bbl on a 260. Because nobody makes adapters.