67 Head Question

[hobsiscool]

In this picture, what is this little plug on the head that the arrow is pointing to? I just got me a 67 head to go on my 81 and I don't know what it's for...I got the plug that came off of it but don't know what it goes to lol...any help?

[hobsiscool]

Anyone?

[463]

it should be the electric water temp sender to a electric temp gauge

[hobsiscool]

Got ya...I was wondering why some folks had it hooked up and some didn't...guess I could replace that plug with a different probe...mechanical temp gauge perhaps?

**edit...guess I could just get another electrical water gauge huh...I see Autometer has a whole range of gauges...

[463]

the hole should be 1/2 in.-14 Thd or 3/8 in.-18 Thd. most parts stores have the brass thread adaptors or there in the manual temp gauge packages.

[70c/10barebone]

I don't believe that's for your temp gauge. It is a temp sender for the trans control spark system. It was an early emission control setup that affected spark advance. I'm no expert on it but I think it would kill vac advance unless the engine was in high gear or on cold starts (hence this sender)

[463]

Originally Posted by 70c/10barebone

I don't believe that's for your temp gauge. It is a temp sender for the trans control spark system. It was an early emission control setup that affected spark advance. I'm no expert on it but I think it would kill vac advance unless the engine was in high gear or on cold starts (hence this sender)

i can't find that sender your speaking of in my part search in the 1981. gm for a while did use a electronic nock detection to retard the timing on the early 80's v8 small block for emissions control. http://www.rockauto.com/catalog/moreinfo.php?pk=40252 but it was not used on the inline 6 cyd. i am still puting my money in the temp sender.

[hobsiscool]

So would I need to use it for a 3 speed manual from an 81? I've seen it hooked up and not hooked up on different setups.

[70c/10barebone]

I'd just leave it plugged with the sending unit in the picture, or if it is missing find a plug to use. No need to use it on your 81 unless you want another gauge. There should be a gauge temp sender on the water neck under the thermostat.