4150 Carb on 4500 Intake

Our class rules require a 4150 carb, but I will be using B1 Original Heads and have the B1 Manifold with a 4500 opening. I also have a 4150 nitrous plate that will be going under the carb.

I would like a 1" open spacer for hood clearance issues. Does anyone make a spacer like this? Or know where I can buy one?

The quick fix would be to swap your base plate with one that is drilled for both patterns. There are adapter plates available, but from memory they are all around 2". A 1" plate isn't going to be feasible due to the two patterns being so close.

quickfuel and holley both have 4150 carbs with dual pattern baseplates .I think AndyF has an adapter plate as well - may be to suit these style carbs on a dominator manifold

Tex

Holley's latest Ultra series carbs also have a dual pattern. Also, if they are legal, an SV1 has a dual pattern....

Yes, I make a 1/2 inch shear plate adapter that works in that situation. You need a base plate with the dual bolt pattern. I've done some dyno testing with this shear plate and it works pretty well. For your application you probably want something large like the new Holley 950.

I currently have a 4150 1000cfm Holley that does not have the dual pattern base plate. Also, the 4150 nitrous plate is another reason for needing the 4150 bolt pattern.

If i buy a different base plate, I also have to buy a 4500 nitrous plate.

Quote:

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Our class rules require a 4150 carb, but I will be using B1 Original Heads and have the B1 Manifold with a 4500 opening. I also have a 4150 nitrous plate that will be going under the carb.

I would like a 1" open spacer for hood clearance issues. Does anyone make a spacer like this? Or know where I can buy one?

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I think you have enough material on your manifold to
take some alum rod and thread it and install in the
4500 holes then re-drill it to 4150... you can glue
the rod in or weld it in... set your 4150 on it to see