I have a 66 with a 352 and a 3.03 on the column manual truck. I think a 3.25 rear end. But I have no tach and have no intention of installing one because I believe it would take away the smooth classic look of the interior.

while I have been driving daily in this truck I have never known the correct point to shift at.
typically I go:
1st - up time 20mph
2nt- up to 40 mph
3rd- whatever speed limit is

what do y’all shift at when driving? Am I doing this right or wrong? I don’t want to hurt anything

 

Always shifted by sound and feel. But now I'm automatic

 

I understand that lol, but don’t know what’s too much for this engine and trans. Wanna make the engine hipo and back it with a sequential, on the column, but that gets expensive

 

Also I’m getting around 6mpg average, most driving is 45-55 mph does that seem low to anyone else?

 

A stock original 352 made it's rated horsepower at 4,000 RPM. It shouldn't hurt it shifting at anything below that for sure. A decent running engine should even be able to handle the occasional short stints at 5,500 RPM without killing it. The 3.25 rear end is I assume a 9" which is one of the stronger production ones built in it's class. The 3.03 is also a fairly stout transmission. I'm not sure if you intend to race your truck but those new Corvettes with traction control might give you a run for your money. Well, it did against a Dodge Demon at least.

https://www.dragzine.com/news/corvet...he-same-night/

 

Yes, that does seem low to me. Most get around 10-12 MPG and with 3-speed and overdrive in Arizona there is a fella on the forum here that's getting a whopping 22 MPG with a 352 engine and I think similar rear gearing. But, overdrive and a good tune can make a big difference. Yours sounds like it might not be tuned to run at peak MPG, but there are usually somes things that can be checked and verified, at least.

 

Yes I think timing needs to be checked, yet don’t have a light yet. What else should I check while at it

 

Spark plugs look like they've been sprayed with black krylon, do they? Ask me how I know.

A FSM will be your friend here. Start with the fuel system. Not just the carburetor, the fuel system. Tank, hard lines, fuel pump pressure. Make sure fuel delivery is at spec. Then setup the carburetor for float height, jetting, and power valve (economiser).

 

They are dark grey if that’s what you mean. I just installed a new fuel pump a couple of weeks ago, I’ve heard that these new ones run a high pressure, so should I get a regulator?

Tank was flushed and cleaned, at the same time hardliners and rubber lines were replaced, new fuel filter as well(type in the fuel pump) this was three months ago

 

Sure that 6 mpg estimate is accurate?

With a number like that the air fuel ratio would be approaching the "rich burn" limit. The plugs will definitely show this, it has to. These old trucks will never get the mileage we'd like, but it sounds like maybe a blown out power valve (economiser).

I'm not really a fan of a pressure regulator as such, because it shouldn't be necessary to re-regulate a serviceable component in the first place. A mechanic's vacuum gauge will also test fuel pump pressure, if it exceeds the spec return it and get your money back, and get a good one.

 

Well I have another new power valve so I’ll just throw that in there to cover it.

 

In the "for what it's worth" department, the 1966 Ford Truck Operator's Manual, page 44, Operating Instructions, Driving With 3 Speed Manual Transmissions, suggests 15 mph as the first to second gear change speed, and 30 mph as the speed to engage 3rd gear. Real world specifics such as the engine and gearing, not to mention the owner's tolerance (or lack there of) for noise, will play it's part in the real world. TA455HO gave you a realistic rpm range. Perhaps you could install sound deadening where it can't be seen. I can remember how noisy I thought my truck was when I first got it and adding sound deadening made a huge improrvemenet. And good luck with your hunt for better fuel economy, After following all those recommendations you should do much better.

 

Typical is a 3.50 but could be 3.25

1st gear stay under 35 mph
2nd gear stay under 55 mph
3rd should bring you to 96 mph

This is assuming you have a tire near 225/75R15

I have found the magic number on timing for these trucks is just as it says in manual 11 deg BTDC but try 89 octane unless you are in a colder climate. Or at least for warmer summer months
Points set to exactly .017 or if you have dwell meter set it that way.
Keep tire pressure up too.
Make sure your vacuum advance is working properly
As Chad said typical for these trucks is 10-12 but a manual transmission 3 spd manual should get 14 mpg if properly tuned.
Mileage will drop off when points start to wear. But, I have found during a ton of testing points seem to be best overall as far as starting and even MPG. They also like the stock Ford carb proper adjusted.

If you want max MPG also try not going over 20 mph in 1st and 35 in 2nd then 60 in high if you can.

I am about to do MPG testing with my '66 352 Automatic with a 3.54 Rear (locking) diff and 225/75R15 Tires. Very hot temps this week 114-116 deg so will have AC on but still hoping for 14 mpg once I get the tune tweaked in.

Since most people have phones or a gps why not use that to verify your speed or try mile markers @ 60 mph.

 

Tachs and vacuum gauges are very usefull and don't have to be a sore thumb. I tend to monitor them more than the other gauges. I'm getting 14mpg highway, not so good around town with a 410.

 

[QUOTE=TA455HO;19428523]A stock original 352 made it's rated horsepower at 4,000 RPM. It shouldn't hurt it shifting at anything below that for sure. A decent running engine should even be able to handle the occasional short stints at 5,500 RPM without killing it.

That's about where my valves start to get a little floaty...