Converting a 4150 intake to a 4500

Modified the intake on Saturday to accept a 4500. Did it in my driveway so I thought I'd throw it up here to show how easy it is.

4500 gasket on the 4150 flange.


Sharpie'd an outline around the gasket.


Drilled holes along the lines I wanted to cut and took a ball peen and tapped the big chunks out. The casting is really thin where the clovers are because this intake is available in both flanges. If I were doing it again, I'd drill smaller holes along the perimeter so I would have less material to remove with the carbide.


I countersunk the alumimum screws, then drilled and tapped the new stud holes. The new holes actually go through the heads of the filler screws.


Finished. I also drilled and tapped a vacuum port in the back because this manifold did not have a vacuum port.



Intake gaskets will be here today and I maybe I can find some time soon to button it all back up.

If you intend to ever use any "plate" nitrous system then remove the front and rear sections of the "cloverleaf" so, it is straight across in the front and rear.

Thanks for the tip!

Easy enough!

Any special tools? Drill press?

Nope. I used a block of steel with a hole drilled in it as a dill guide and drilled it with my 1/2" hand drill. Drilled, tapped, done.

Nice job. Thanks for posting the pics, it's going to make it easier for me when I do mine.

Thanks! I am going the other way with my intake. Where did you get the alum screws???

I ordered them from Mcmaster Carr.