'81 flareside 4x4 project

Mat,

I definitely agree, if the installers used the original studs/bolts, there is a potential of catastrophic failure.  I googled lift spacers for our rigs last night, there are some still available.  They come with an extension bolt to install.  That being said, my plan is to disassemble and remove these spacers and see if this improves the ability to get the alignment to spec.

I will have to see how the rear lift blocks and ride height looks after I pull the spacers out.  The truck sits nearly level now, so I anticipate needing to address that at some point too.

I truly appreciate your help, I absolutely think this site and the members are fantastic!

very good. the one thing that could show up in this is that if it has an extended length bolt for the added spacers then it may be far too long to go back in place without the spacers without interfering with the axle. that means you may need to replace them if you are not comfortable cutting and beveling them.

Mat and Rembrandt were correct!  I removed two obvious homemade spacers today that were 11/2” long. They were definitely built solid, but really messed with the front end geometry.

Dropped the font to what seems about right for a 4”lift. With any luck I can now get this rig into alignment.

Thanks for the help figuring this out!
 

Well done guys!  

please tell us the details of the bolt. don't leave me hangin bro!

Sorry about the Mat!  I should have snapped a photo while apart, but was in the zone...

The bolt was very long to accommodate for the spacer, with a large nut on top.  I looked inside of the axle housing and there were threads showing beyond the nut in there.  It was kind of close to the axle, but I figured it was a solid one piece stud/bolt.  I may regret not disassembling it to know for certainty, but I didn't want to struggle with double nutting the bolt to get it off.

So I now have a very long bolt, I just ran down the nut to tighten it all back up.  Thought about trimming it shorter but really saw no need as it does not interfere with the suspension, only the hassle of running the nut down a longer than necessary bolt.  

I have ordered new pivot bushings and radius arm bushings, I'll snap some photos when I tackle them to show the results of removing the spacers.

here is a close up of the mounts now.

that will work. it hurts nothing where it is and as soon as you have all settled and running true reach in there with a skinny brush and coat it with anti-seize or grease at least. no sense in letting it get rusty. but im glad to see that it was done well at that point.

It has been quite a while on any updates here.  I have been driving the truck, although the summer heat has really slowed this down since I dont have working AC.

I have been chasing vapor lock issues too, the truck really suffers when in excess of 100 degrees.  Odd thing today was I decided to drive the 10 miles to work, started acting bad about two miles in, hardly able to exceed 40 MPH.  About half mile from the office, it was like someone turned on a switch and the old 351M came to life!  Not sure if there was a blockage in the tank or if an air pocket cleared out, but the truck ran great the rest of the day.  

Has anyone ever used the evap line for a vapor return?  The charcoal canister is long gone, but the small diameter line is still there and plumbed to the tank.  I'm considering getting a return style fuel filter and plumbing it to the line to vent the system back to the tank. the tank has a venting valve with a small orifice (from the evap system) that I think may help with the vapor lock as fuel will continuously cycle.

Let me know your thoughts, this rig runs too well to leave at home in the heat!

Do you mean a return-style fuel pressure regulator, not a filter?  If so, then I think I understand.  But wouldn't that cause the system to eventually have a vacuum on it as the fuel is removed with the engine running?

We have a thread about that called "Fuel tank rupture caused by negative pressure????"  You might read that to see what you think.

just getting back here after a while. trucks have kept me very busy. I too have a 351m that I have been resurrecting. I just replaced the rear tank as an assembly. it is full and still I'm not getting fuel. I will figure it out but there may be a similarity to yours. mine I started last winter and started with a new front tank assembly as usual. I hate fuel problems. and old fuel in a truck left neglected is about as bad as it gets. tank to carb reworked and runs beautifully.  however, I leave this truck at the garage. and use it as a tow vehicle occasionally. my brother tells me "Hey I used your truck to go pick up a set of wheels for an f 350". as it turns out he did not remember that the rear tank was still junk. as it was delivered. so, he ran crud through an already cleared system.  all good he says, it is full.  he tells me this while towing me home haha. how can I blow up? he is towing me home!  now I take responsibility overall due to having not replaced the rear tank by now, but it is truck number 9 on the list!  not my first priority. and then there is the sign. taped over the tank switch etc.
back to the point. the tank selector valve is a possibility. mine is getting voltage and I have blown compressed air backwards to remove a horrible amount of debris yet on the rear tank setting the fuel pump seems to be pulling a vacuum on the fuel line. meaning it is still clogged or the tank selector is stuck in one position. another possibility is a bad ground. getting voltage to it is not the same as through it to ground. after now replacing both tanks ,sending units, vent valves and their gaskets. ,hoses, filters and rebuilt the carb (twice now) there is only the selector valve as a possibility. oh and gas mpg sucks. tbe!

I hate to tell you, but Dad said his '81 with a 351M got 10 or 10 or 10 MPG depending on how you drove it.  My brother says his '85 460 got 10 or 10 or 10 depending on how you drove it.  Guess which one would tow and go.  

Hi Chuck, Excellent project truck you got going, I wanted to comment on the XLT trim,
I think it really adds to the truck, and with a flareside, you can be creative and adapt it to your own
preference. I did that with my truck with the wheelwell trim. I took the styleside box trim and used it on the flareside rear fenders and I think it looks really good!

Gary,

I was talking about something like this filter with a built in bypass/return.  I believe they have a small orifice to let the excess vapors bleed off similar to a regulator (just not adjustable):https://www.amazon.com/WIX-Filters-Complete-Line-Filter/dp/B000C9UJAA/ref=sr_1_3?crid=7LEBYB1FWC77&keywords=bypass+style+fuel+filter&qid=1689563825&sprefix=bypass+style+fuel+fileter%2Caps%2C148&sr=8-3

As far as the vacuum building, that could be an issue, although since this truck and the original filler neck and hoses are in place, I bet it is venting itself...

Hey Mat, thanks for chiming in.  Bummer about your #9 priority rig, hopefully it did not ingest too much into the carb and you can clear it out.

I only have a single tank night now, all of the valves are bypassed so I don't think that was it.  I am curious if the sock arounf the inlet in the tank may be plugged up and I happened to unplug it when it came to life though.  Probably need another fuel filter change in case it pulled it into the line though...

Chuck

Jeff,

I wish I had your skills and abilities!  Your rig is exceptional and I can only hope to get in the ballpark of what you have gotten done!  In fact, thanks for sprucing up my project page

I may have a line on a complete 82 styleside truck with a good front clip, great doors and 6' bed with the XLT trim.  Kind of considering taking this truck back to stock with a styleside bed but having mixed feelings about that.  Since my front fenders now have the XLT trim above the fender, or at least the holes for the trim, I need to figure out if I'm going to fill them and repaint similar to what you did, or try to finish the rest of the truck out with the trim too.  

I cannot find the trim on any of the common truck websites, and can only imagine the cost if I did.  If I can buy the parts rig reasonable, at least I would have all the parts to trim it out.

Thoughts  from everyone are welcomed.

Gary, as I mentioned earlier, I recently changed Big Brother's tires, preparing the road trip.

With his all-year-long winter tires, Big Bro used to drink around 9mpg, 10 with a back wind and rolling down a slope.

His new consumption is 13mpg.  I am flabbergasted
Tires weren't cheap, but wow, what a difference!
And not to mention the comfort and the huge noise reduction.

Gary Lewis wrote

I hate to tell you, but Dad said his '81 with a 351M got 10 or 10 or 10 MPG depending on how you drove it.  My brother says his '85 460 got 10 or 10 or 10 depending on how you drove it.  Guess which one would tow and go.  

Gary, as I mentioned earlier, I recently changed Big Brother's tires, preparing the road trip.

With his all-year-long winter tires, Big Bro used to drink around 9mpg, 10 with a back wind and rolling down a slope.

His new consumption is 13mpg.  I am flabbergasted
Tires weren't cheap, but wow, what a difference!
And not to mention the comfort and the huge noise reduction.

Wonderful!  That is a huge improvement!  

My vapor lock issues came back again today.  I was down under a 1/4 tank and headed to a gas station when it hit.  Barely made it there, gassed up and headed home.  It never really cleared up and was running poorly and never able to go above 40 mph.  Got home and decided to blow air back through the line into the tank in case the sending unit sock was blocked.  Tank was full and burped gas from the fuel filler and gas cap area when I did it.

Put it back together and the darn thing still suffers.  I am still not convinced it is not a blockage in the sending unit though, since it came on suddenly, and the last time it cleared up it was sudden, like someone just threw a switch.

If it is true vapor lock, I still may try to use a filter with a bypass (see link a few pages above) and use the old charcoal canister canister line back to the tank. I was hoping to avoid dropping the tank to look at the sending unit, but I just may have to.

Any insights are welcome, this long hot spell (109 degrees today) in our area has been tough to deal with and I'm still not convinced the problem is not fuel starvation.

What about your fuel pump? Have you checked or changed it?