What we have are a pair of Weber IDA based throttle bodies that need to mount on a Thickstun dual 1bbl intake.

The intake is a modern reproduction of the original Thickstun intake for the small Chrysler flathead six. Made in the USA, these pop up on Ebay for sale every so often , if none are listed the link below takes you to the seller's page.

A pair of Weber based throttle bodies, 42mm bore size perfectly matches the bore of the intake. You can buy them with injectors, but no specifications are given so I bought without and got my own injectors elsewhere.

Here I have placed the TB's on the intake, if you look you can see that the TB's have a mounting pattern at an an angle other than perpendicular to the throttle shafts. The intake has a bolt pattern perpendicular to the throttle shafts, an adapter is needed. The connecting link between the TB's shafts are standard 8mm round shaft and couplers. The black lever between the TB's is recycled from the intake linkage kit.

First I needed the spacing of the various holes involved to draw up an adapter, remember when I took drafting it was paper and pen, not CAD. So I draw things up by hand. I needed the dimensions of both the TB and the intake mounting points, plus the angle of the TB's pattern.

A pencil, some paper and a mechanical dial caliper, not a single luxury but the meat computer in my head. That's how we did it back in the day. Here we see the drawing and math I did to determine where to put the holes and how big to make them.

I used a 3.5" file card because it was stiff enough and big enough to work. The X marks the center of the card and the bore. The horizontal line is marked for the intake's mounting holes, the offset leg of the X is marked for the TB's mounting holes. I got the angle of the Weber's pattern using the eyeball method, sort of.

I used a 3/4" thick piece of phenolic laminate, cut out two 3x5" pieces. I went with 3/4" thick because I may have to add two fittings in the spacer for a common vacuum source to feed the MAP sensor, jury is out on that. Otherwise I probably would have gone with 1/2".

Taped the template to the laminate and used a finish nail and hammer to center punch the center lines, all 5 of them. 2 for the Weber, 2 for the intake and 1 for the center bore.

Here you can see the completed drilling, no shots of me on the drill press, sorry. The center bore was done with a 42mm hole saw, the other four were 21/64" with the two holes for the intake mounts countersunk with a 5/8" spade bit to take button head screws that sit below the surface of the adapter. With phenolic use the slowest speed you have or it will burn.

The TB's will mount to the adapter using button head screws, I am inserting helicoils in the adapter for them to screw into. Some might say you don't need to do that, those people don't touch my stuff. I bought this kit in 1994. You never know when you will need a tool, so buy quality and it lasts.

Here you can see the the tap cutting threads into the laminate for my helicoils. The tap is a special one used for cutting the proper threads for a 5/16-18 helicoil, which requires a 21/64" hole, the tap is marked with the size drill needed. Now you found out where I got that size when I marked up the drawing. The video linked is how I tap. Some people chuck a tap up in a drill and have at it, those people don't touch my stuff either. Nor do the ones that don't do the back rotation.

I am winding the thread insert into the laminate, I set it just below the surface when done. Before you start winding it in, double check the tap job as I had to re-tap two holes as laminate is finicky. Once the insert is installed visually check those threads as well and make sure they are uniform, then run the bolt in as a final check.

I've bolted the adapters to the intake and dry fitted the TB's, linkage attached, to test the fitment. Looks good at this point, but I did find an issue not related to the adapters, we'll get to that next. You can also see the final pattern for the adapter's shape as well, we'll also get to that.

I had planned to use carb mounting studs to bolt the TB's to the adapter, taking the wear and tear off the inserts. But as you can see here, I cannot get a washer much less the nut past the protrusion on the TB. So I will use cap head stainless screws instead. But a bit more finicky mounting the TB and gasket but it is what it is. We press on. You can also see why I had to counter sink the adapter to intake button head screw. I suppose I could of used a countersunk screw instead.

I will be using a carb base gasket between the adapter and the intake as well as the adapter and TB, the original base gasket for the Cambridge will work in all four places. Here I have aligned it with the TB mounting holes and will draw the outline on the adapter. I will do the same for the intake mounting holes to give me a general outline.

The radius around the adapter to intake bolt holes was too small, remember the counter sink there, so I used a socket with the proper diameter as a radius. I put a short 1/4" extension down the center of the socket to line it up with the bolt hole, worked pretty good.

Here we have the finished outline of the adapter, all that is left is to cut and sand it to shape. Sorry, no actions shots either, nor video links. I try to keep the videos links limited to videos that are to the point without extra nonsense.

I don't have any shots of the done adapter before installation, sorry. It took one day to do them, I made two rights, then had to make a left because I forgot they were handed till after I drilled the counter sinks, up to that point they can be either side. Painted them and let them dry overnight, then bolted it together. Nothing binds, everything clears, other than that issue mentioned above, waiting on parts there.