2 inches

 

Ok. I've got one of those ultimate carb screen things on there, and it fits. I've got to have three. It's not an issue then.
Thanks, mike.

 

I decided to find out how close was too close on my car. 4" cowl hood. I just kept stacking spacers on. Finally the car just died at 600'. Took off 1/2" spacer and it ran the same as it did with no spacer. 2" was my minimum with a cut hose between the vents tied over to the side

 

I can tell you that i tried a 3" filter with 1" of drop for 2" clearance to the filter top and car would not run in high gear at all. Took off filter for 3" to the hood and runs wonderful.

 

I orginall had about 3.5" when I first built my car.

When I put the Dominator carb on my car last year, I had to use one of those Moroso 4150 to 4500 tapered adapters..... the front vent tube was actually touching the hood scoop.... but it didnt seem to matter as the car ran its personal best like that.

I did fully convert the intake manifold to the 4500 bolt pattern this year to get the carb to scoop back close to where it was orginally. Yet to finish the rest of the motor so I dont know if it'll help or not.
Will

 

Good stuff. Thanks for all the input guys.

 

3" over the vent is my suggested min

 

This......

Some pro stock guys will tell you 4" minimum.

I have seen tunnel ram cars go dead @ 500' with 2" clearance.

 

running deep in the 8s with less than 1" over the vents

 

We had vent tubes tight to the cowl and were fighting a tuning issue on the nitrous; rich/mixed looking plugs and a surge after low gear. Cut the hood for a lexan scoop, issue went away and the car picked up a bunch.

 

I might be thinking of this wrong but if some are saying 3-4" minimum wouldnt the air cleaner lid be a huge restriction as well? Some of those with a 4" element and a drop base cant be farther than 2" i would think.

 

Talked to Gary Stinnet about this at the last divisional race, he told me 2-3 fingers between the top bowl vent and the hood.