SW sending units in Edelbrock head??

Ralph Moore

Well-known member
I have Edelbrock 59AB heads and Stewart Warner sending units. Went to put these in and the thread does not go in more than a 1/4?turn. I don't want to strip these heads, are the sending unit threads metric? Or made in PROC crap?
 
The heads should be 3/8 NPT, which is a tapered thread. You should check the sensor to make sure it's the same thread. You might just have to run a tap in alittle further.
 
I can't answer your thread question, but I can tell you that Edelbrock castings are produced in the USA from start to finish. Design, engineering, casting and machining are all done here. Vic E. even purchased an aluminum foundry to do that in house, keeping the operation 100% Edelbrock and 100% USA.
 
I believe SW gauges are made in Mexico. My SW sender is screwed into a brass fitting that screws into the head. It is included with the gauge.
 
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Checked heads with tap they are ok. I have the adapters that came with the senders, but they won't go in. Can a standard 3/8" x 1/8" pipe busing be used, or are the sender threads special?
 
Checked heads with tap they are ok. I have the adapters that came with the senders, but they won't go in. Can a standard 3/8" x 1/8" pipe busing be used, or are the sender threads special?

Check the adapter to see if it will screw in something like a standard street "L".
Check the heads by trying to screw a standard pipe nipple in.
This will tell you which thread is at fault.
 
I had the same problem with my Edelbrock heads. I tried different pipe fittings and nipples - same problem. You are likely going to have to run a pipe tap slightly deeper in the head to get more engagement with the sender(s).

I assume that the heads are already installed. If so, push a small rag into the hole, apply grease on the tap and turn it in a half turn after it starts to cut. Remove the tap. Most of the shavings with stay on the grease, but some will fall in the hole, hopefully most of the shavings will be captured on the rag. Use a thin pair of needle nose pliers and pull up on the rag and use air to blow chips up off the rag and out of the hole. You will likely lose a few chips down in the water jackets, but not many if you are careful.
Try the sender again. You will probably have to run the tap in the hole again, but this is better than trying to go too far at one time.

Not the best solution, but it beats removing a head(s).

I'm sure that even experienced engine builders learned the hard way to check sender, pipe plug and even spark plug engagement before installing the heads.

Good Luck!
 
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