Keep in mind the adjustment screw is only for the idle jet/mixture.
The only way to check the main jets is to check the color of the plugs. Don't remember if I was told or read it in one of my old manuals, but the best way is after the engine is good and warm, to pull a long grade, pull over and shut off quick so idling doesn't carbon them up, pull plugs and look for that nice tan color.
Dark/black = jets are too rich (big). Totally white out = jets are too lean (small). Change one jet size at a time until you get that nice tan color.

Gawd I love old school! F that ECU/SCT crapI!!

 

Wow. Lots of info.
I'm going to check out my transmission first. Sounds like a reasonable explanation since the engine seems to be running smoothly. Can I check the temp on the tranny with a laser thermometer, and approx what temp should it be? Then I'll start everything one by one.
Thanks

 

And I'm pretty sure it's a 3 core radiator, but looks real thin. Def not 1" rows. Only about 2" thick. $300 for a 4 row aluminum radiator isn't really in my budget right now, but I'll get on it asap.

 

No A/C

 

Also it's an automatic. I'm going to do the rpm/speed test today when I finish work. I'll get back with the results as soon as I know something.
Let me get this right. I should run it in first or secon for a period of time at higher rpm's and see if it gets hot?

 

Houtex said. "...The exhaust going quiet at the 65 MPH mark is... disturbing..."

My 69 Galaxie w/ new duals did the same thing, went quiet from 65-70 & I never had an overheating problem. Sounds can 'cancel' out each other if the pitches are right. Weirdest thing ever was when I sat idle next to big city diesel bus, you could not hear either exhaust. Eerie silence.

 

If it's a 3 speed auto, then yes, 2nd at the SAME RPM. You are trying to determine if the speed or the RPM is the key to this whole thing.

If the car runs at 3000 RPM at 65MPH in 3rd, then put it in second and run down the road at, oh, 40 @ 3000RPM, or whatever the MPH winds up being.

That being said, just now, I realized that it could be the 3rd gear in the trans doing it, so the test won't do anything to say RPM or speed, but I kinda doubt it, I bet this does something to help you figure it out.

I hope.

 

Everything seems to shift smooth and runs great... Just gets hot. Heating up faster now that it's hot outside.
I'll keep you posted.

 

I'll also take note of when it shifts (at what speeds) see if that helps

 

Is it possible that the 3 spd auto tranny in my car has overdrive? Would that explain the quietness at 65? If so, how could I look at it and tell? It was originally 6 cyl and manual shift.
Just a thought...

 

Anyone know of a good mustang guy in the Atlanta area??? I think I need help. Haha

 

Any general mechanic should do, especially if they're old school - I'd find a lot that 'missed the old days' and loved to touch antiques. I don't think you necessarily need a Mustang guy (or girl).

Did you by any chance check for water flow? I don't remember seeing it mentioned.

 

I checked the water flow. I just got it warm and, with the radiator cap off, I revved the engine. The coolant moved about 1/2" when I hit the throttle. Enough?

 

Well boys. It's raining. Just got off work won't do much good to do the speed/rpm test tonight.
One thing I did figure out:
If I drive it in 2nd gear exhaust gets quiet at approx the same rpm range. Not sure what that means, but food for thought. Haha

 

http://www.cjponyparts.com/radiator-...1969/p/RADA33/

Does this radiator seem sufficient to cool my engine?? I know it's still a 3 row and it's 2" thick, but it's aluminum...what do you think?

 

What mix are you using for coolant & how old is the radiator?

 

I'm using 50/50 coolant to water and the radiator is less than a year old...

 

New water pump going in today. I'll keep you posted.

 

They gave me the wrong water pump! **** you "Auto Zone"
I'm giving in and taking her to a "real" mechanic in the morning. I'm spending more money trying to figure it out. I'll let a professional see what they can come up with. I really hope these guys can figure it out. The owner of the shop drives a very nice '66 Mustang. I hope that translates into me getting out on the highway soon!

 

Wrong pump? Get the right one! Easy-peasy.

Blades too small or something? How'd that happen?