[601HP]

I run the Holley 600's on top of a Tunnel Wedge intake. I use the S&H base and top, and K&N filters. The choke horns have been milled off.

Early on I replaced the S&H filter guts with K&N filters. I still wanted to get a taller filter installed, but I had no space available. I looked at how I could lower the S&H base.

a. I Milled off the lowest flange of each S&H base plate.
b. Then drilled two holes in the S&H base plate where the carb float level adjusting screws/nuts are located. Also had to slightly modify the bottom of the K&N filter's rubber base to allow it to sit on the float screws/nuts, because they now protrude through the S&H base plate.
c. After doing the above, the S&H base plate contacted the top of the vacuum secondary cover, and would not sit level. That secondary cover is plastic on my carbs. (I use the quick change covers) So, I slightly ground down the top of each secondary cover with a Dremel tool.

All the modifications are hidden when the pieces are in place.

The S&H base plate rests on the body of the carburetor and I gained about 1/4" - 5/16" reduction in overall height, which allowed me to use a slightly taller K&N filter.

I used the KNN-E-2570. It's 1.875" tall.

David