1957 Chevy truck re-rebuild

[Stepside Jim]

The truck is back in the shop, it's upgrade time. Two upgrades are on the menu, first the turbo 350c trans has done well for 10000 miles along with the Gear Vendors overdrive.

First upgrade is the transmission, I know the Th350c is not the strongest although I did put stronger parts inside of it, I always took it easy while shifting, ect. I also had a 3000 stall lock up converter which was a great combination. This 3000 stall converter is why I went with the 350"C", it has a lock up converter. I have the best of both worlds, great low end, then at highway speeds, over drive and lock up the converter.

Must have been time to upgrade, I went to the junkyard for something else and sitting there was a 4l80 that had "Bad" written on it and it had the 4x4 tail shaft. These 2 situations made it the least desirable, sold $100.00.

The tail shaft issue was easy, e-bay and a 2 wheel drive tail shaft acquired. I've been purchasing parts for months now and am ready for the upgrade.

Parts, new shifter for 4 speed, torque converter, major overhaul kit, shift kit, new electronics, TCI ECU, Gear Vendors adapter, Throttle position sensor, Torque converter cover, Ring and Pinion and other odds and ends.

I'm sold on the 4l80e since I removed a Th400 in a customer car and installed the 4l80e. Overdrive, lockup converter, push buttons to change the shift firmness, set RPM shift points....sold.

[Stepside Jim]

I decided on a torque converter from TCI that is a 3000 stall. It has a multiple lock up disc upgrade which I like, its supposed to handle high horsepower with the lock up engaged. It also is a bolt together converter meaning it can be worked on with out cutting it apart and rewelding it back together.

I've found in the past that the stock 4l80e converter flywheel bolt holes did not exactly match the bolt pattern of old style flywheels. I did a prefit test and it looks like TCI gave it multiple bolt patterns so it fits nice.

I decided to assemble the empty trans case and overdrive and fit it into the truck. I've been able to have the driveshaft fitted and found a slight interference of the bellhousing to header to starter, nothing that removing a bit of aluminum couldn't take care of.

My old exhaust had to go through major changes, Ill show that next post.

I'll be able to remove the old kick down cable and vacuum modulator line also.

[dsraven]

what is the final gear ratio with the 4l80 final ratio and the added o/d final ratio? at highway speeds what kinda engine rpm will you have in high gear with the o/d engaged and lockup on? just curious why the added o/d unit with the trans that already has an o/d, do you have a super low speed axle ratio then? not being critical here, just curious.
your truck looks super clean underneath. nice job.

[Stepside Jim]

dsraven, your curiosity is as mine was once I decided to do the double overdrive.

With the TH350 and Gear Vendors and 3.73 rear end, I ended up with a final ratio of 2.91, plus or minus.

With the 2.91 ratio at 65 MPH I was approx. 2100 RPM.

My new numbers changing to 4.11 rear and double overdrive puts me at 2.50 final ratio. Dropping me to 1800 RPM at 65 mph.

Rarely with the 2.91 ratio did I need to change out of O.D. so I figure I'm right on the fine line here.

I'm always looking at what changes I can make to have more fun with the truck, being able to go with a higher ratio gear start off, then going to the other side of the possibilities and easy cruise at 65 or more.

Now, this is not cheap, I don't care. I committed to do the best I possibly could back in 2011. Regardless of time or money.

[dsraven]

Interesting. You wont know till you get it back on the road I guess. Curious how the 4L80 will do and if it wants to hunt for lock up/overdrive at certain rpm's. You could always swap the rear ratio if need be. What axle do you run? An axle with a 3rd member could be like a poor man's quick change if you had another
3rd member with a different ratio to swap in for testing, if it hunts a lot. Nothing more aggravating than that constant fear change. I hate my 2015 trans for that reason, and also the v4 mode.

[Stepside Jim]

You bring up some good points on how the ECM will react. I'm going with a TCI brand control unit, it has a fair amount of options for shift points ect. It also has an option for manual control over the lock up converter.

The Gear Vendors does have a control unit, it pretty well just works off a speedometer speed signal, it turns on overdrive and turns off overdrive at set speeds. It does also have a manual switch that allows you to be in full control of overdrive.

Hopefully I'll have enough options to get the results I can be happy with.

Progress wise, with the trans case still empty and light, it's easier to get all the odds and ends fitted or refitted. The old crossmember needed to be altered, the driveshaft shortened and the exhaust redone.

GM puts a perfect indentation in the pan for a drain plug, Amazon had the perfect drain plug kit. Drain plug installed.

[Stepside Jim]

Changing from the Th350 to the 4l80e has taken space where the old X pipe for the exhaust cross over from side to side.

My next choice is going to an H pipe. Why go with either one, sound, my exhaust exits both sides of the truck and I want all 8 cylinders sounding on both sides.

The X pipe did this easily since all 8 cylinders mixed at one point. My issue with an H pipe is the exhaust doesn't travel and mix together, the exhaust pulses hit each other in the middle of the H pipe but nothing really travels back and forth.

I came up with what I hope will solve my problem and only need the space of an H pipe. I call it Strex pipe, a stretched X pipe.

The pics will tell the story, in short, cut lengthwise the H pipe, slip in a piece of 18 gauge sheet metal, now the pipe is two pipes in one once welded back together.

Place angled fins to capture exhaust on one side, send it through the split H pipe, where the angled fins direct the exhaust to exit and flow with the exhaust in the other side exhaust. The exhaust from each side passing through the H pipe never touch each other making a free flow yet mixing all 8 cylinders together in the end.

I haven't started the truck with this setup, but hey, this is Hot Rodding. There's something about thinking and always trying to find new ideas that keep me moving forward.

[Stepside Jim]

Trans rebuild was almost done, I had all the internals in place. Then I was watching YouTube and realized I thought I had all the parts for converting this 4x4 trans to a two wheel drive...Reluctor ring, the cogs are what the speed sensor uses to tell tell the ECU the tail shaft speed. First time dealing with electronics in a transmission.

Amazon got one to me in 2 days, and I saw where another fellow put one part in the freezer and heated the ring and they came together without a press. Sure enough, I froze the drum and heated the reluctor ring with my heat gun to 250 degrees, just a small tap tap and a perfect fit.

Nervously I finished the reassembly and tried to cover every issue along the way.

Next was mounting the TCI ECU box, I had plenty of space under the drivers seat, and sent all the wires down through the floor. I had to mount a Throttle position sensor and module to use my HEI RPM output. Had the main harness for the trans and the tail shaft speed sensor wires also.

Lets see, had to have the driveshaft shortened, remake some of the crossmember, changed up much of the exhaust, change the shifter to accept 4 speeds and also changed rear gear ratio from 3.73 to 4.10.

Around 7 quarts of trans fluid and lets see what happens....oh, and around 28 ounces in the gear vendors overdrive.

Fairly uneventful, just as you'd want it to be, let it run for about 30 seconds and add 4 more quarts, start again, try reverse, yup, try forward, yup.

No leaks, check all bolts, check fluid level, add as needed. Back out of garage, slow roll to street, take off slow, second gear and so on through to fourth gear.

Only about a mile drive, back home check fluid level, no leaks, another test drive. All four gears, switch on Gear vendors over drive, then switched on lock up converter, all worked.

More to the story for later, but I have check my speed with GPS to my RPM. At exactly 60 miles an hour with 4.10 rear end, both overdrives and locked converter I'm happy to say 1650 RPM, mission accomplished.

[Stepside Jim]

The 4l80e was nearly a perfect switch except for one issue, one that I hadn't heard of until now with this set up.

This truck is to have great off the line torque/drive, that's were the 3000 stall converter and 4.10 rear gears come into play.

I also want low rpm highway cruising speeds, that's were double overdrive and lockup torque converter come in.

My test drive showed an issue coming to a complete stop at idle in drive. The torque converter pulled/dragged the engine rpm down about an extra 100 to 150 rpm. The instant I began to roll, the torque converter would free up to a normal stall loose feel, stop immediately and the drag effect would happen.

Thanks to the internet, since the tech line that I called was pretty much no help, I found I wasn't the only one to experience this dragging issue.

Installing a shift kit raising pressures and a multidisc lockup creates a sensitive pressure situation. Thanks to Sonnax products, they make a pressure relief built into a valve up in the pump. Installed and went for a 30 mile drive yesterday, all seems good now.

Next on the to do list is making a Gas Tank for under the bed. I've just never been happy with the ones I see available, so here goes. Staring with a carboard mock up. I'm looking for a little over 20 gallons when done.

[Rickysnickers]

There was a post today where another member was asking about the possibility of installing a 4L60 into his '57. Your fits. did it require any modifications to the floor or transmission tunnel?

[Stepside Jim]

Rickysnickers, I put my 2 cents in...

Ok, gas tank, yes, I wanted it out of the cab when I built the truck for two reasons that are not commonly mentioned.

First, I can very slightly smell the gas while driving down the road, it's barely detectable. I'm not happy with my sinuses because, I have to have everything fragrance free or I'll get dizzy, it's a pain in todays world were even with garbage bags I have to look for fragrance free.

So, over a long drive I start feeling light headed, out comes the cab tank.

Next, the factory tank has no baffles, if I want to get heavy footed and drift sideways, and with the tank being long, side to side, and I don't have over 1/2 tank of gas, I will starve the pump and run lean.

I didn't much like what was available when I built the truck, most were hanging lower than I liked to get near 20 gallons. I didn't want to remove the cross frame that went between the rear leaf spring shackles to get a higher sitting tank back then.

After having issues with frame mounted electric pumps and hearing them run I've decided to go with an in tank pump.

I contacted Tanks inc, for advice and parts, very helpfull.

When done I should be around 21 gallons, under bed, quiet pump, baffled, fairly out of sight of which it will also be painted satin black.

The cardboard mock up gave me an idea of size and fit. Then slight redesign, and off to the plasma cutter.

I'm going with 1/8" aluminum and will weld near 30 feet. I don't have a press to bend 24 inches and my sheet metal pan brake will not bend it either, so I'm stocked up on welding rod and Argon.

Disclaimer, I'm not disassembling the old tank till this new one is done and I'm confident with it. It's Hot Rodding, I like to raise my bar and push my limits, so here goes.

[Rickysnickers]

I saw that, thank you

[Stepside Jim]

I've been putting miles on the new transmission, so far so good. Using the TCI ECU, I've been dialing in my high speed shift points and my low speed shift points also. The Sonnax valve is working perfect, no more dragging feeling at idle in gear. The new exhaust sounds spectacular. The 4:10 gears, more fun to drive than before.

Gas tank is coming along, my aluminum welding has significantly gotten better. You can practice Tig welding scrap pieces all you want, it's not til you want to weld 24 inch welds over and over til you know you're getting it more figured out. Then have to weld 1 inch diameter bungs for vent fittings and a 1/4 npt outlet.

After some very accurate measuring I committed the Plasma Cutter to cut the side panels. I need very close accuracy so the fit up will give me the perfect "v" for welding the outer edges.

Yes, baffles, I decided not to do the big baffle thing, let it slosh. I chose to focus on keeping 1 1/2 gallons at the pump inlet. My holding area has slits cut in the bottom to allow gas to fill the holding box, but keep the gas in there while hard turning and acceleration. Having the bottom of the tank tapered to the holding box I believe will help.

Pictured is the in tank pump from Tanks inc. More on that later..

[Stepside Jim]

When I looked at the pictures of in tank pumps that will work for homemade gas tanks I never saw a close up to fully understand how it all fits and works. So here's a better pic.

One unit takes care of mounting flange, an adjustable capture tray, high pressure pump. The top mounting plate has 3 pipe thread openings. 1) for main pressure out line, 2) bypass regulator return line in and 3) vent line. I'm not using the vent line, simply thread in a 1/4" npt plug. Oh two wire holes to feed wires through. They installed special compression fittings to seal the wires.

The fuel pump has a specific sock that is a pre-filter attached.

The next pic is a better pic of how I decided to manage the gas getting into the gas capture area.

[oldman3]

Hey Jim

I'm not an engineer, or anything close to it. Nice work on your tank.

I believe all liquids, seek their own level. If so your taller tank will only fill to the same height as the shorter tank. It would have to be under pressure to overcome the difference.

You can do a test on the tank before installing, by adding water through the fill. You may be a few gallons less than than what you think.

I could be 100% incorrect, let me know how it goes...Jim

[Stepside Jim]

Ahhh, I started to reply a theory, then I clicked back to see what pics I've posted and what they show.

The two openings showing in the lower section seen is the large opening for the pump, it's 6 1/2" diameter. The smaller opening is for the sending unit. These two I was able to measure and plasma cut when I cut the top panel.

One opening in the pictures not shown is the gas cap opening, it will be located in the higher level on the drivers side. I wanted to build most of the tank then get it in place and mounted. Without the bottom panel welded in place, I'll measure closely where to hole saw the gas cap opening. Once I made the opening in the tank, I'll put the tank back in place and use it to sharpie mark the hole in the bed.

Thanks for checking in oldman3,

[oldman3]

Yes the fill in the taller tank will take care of everthing. I thought the fill was in the lower tank. Sorry about that. You know the old saying when you ASSUME somthing...Jim

[dsraven]

I just dropped the tank in a gmc envoy and that thing has a shape sorta like this, a couple of high spots. GM has vents at the high spots to allow air to escape when filling so you can get an actual full tank and also, I imagine, so it doesn't burp back through the filler when the bubble in the high spot decides to move when filling. also so it doesn't take forever to get a full tank.
I just dropped the tank on my project that is sitting on an 04 gmc envoy frame. the fuel pump croaked. the tank is very uneven on the top but it also has vents on each high spot. the filler is at the rear and each area where there is a tie down strap, and corresponding crossmember, has a corresponding low spot in the tank top.
https://www.gmpartsgiant.com/oem-gmc...fuel_tank.html

[dsraven]

dunno what happened there but I started a post and then it got lost so Irestarted it and hit post, then it has both parts. oh well, you get the odea anyway.
use a larger hose for the vents that connect the high spots, I think the envoy vents through a cannister but as long as the highs are connected it should still fill.

[dsraven]

make sure the gaskets on the two holes in the lower part are good solid gaskets because thats where the leak will be, if anywhere, due to a partial tank of fuel being above that level when the tank is full

[dsraven]

having the sending unit in the lower section means that the first portion of the full tank is going to read "full" until the tank is used and lowered to the level of the lower section. correct?
how tall will the filler neck be, in your estimation?

[Stepside Jim]

Ok dsraven, you are right on target.

The filler neck is around 1 1/2 inches long depending on if you count thread length. I bought one that was called a 2 inch and I cut 1 inch out of it. I figured every bit I could keep the tank up to the bottom of the bed is all the higher I could raise the bottom of the tank.

You mentioned venting the tank at the high points, yes, the vents are what will in my theory, allow the two step tank to work. There is a tee at the back/higher section. This tee allows the front section to breath into the tee when being filled, the higher section also breathes into the tee and there is a line coming off the third tee outlet that will 90 degree around the back of the tank for fresh air.

dsraven, you are correct on the gas gauge waiting till the level drops, I figure around 25 to 30 miles before the needle starts to move.

The vent hose coming off the front section has a upward curve for two reasons. One, it can't pool gas in it and block air flow. Two, it curves up over the cross frame that gets in the way of most under bed installs.

More to come.....how did I attach the tank to the frame, where does the vent hose go to, how did I support the hose across the rear of the tank and be assured to has a slight upward angle, what to do to make steel braided hose attachment possible without dropping the tank. Oh, what 5/8" miscalculation did I make that makes the back of your neck sweat and you're heart rate raise.

[Stepside Jim]

I'm gonna get away from the gas and vent part of the gas tank build and focus on how to mount it to the frame.

What I don't want and what I do want and how to make my wants work.

I can't use straps easily since I've left the cross frame in place and many aftermarket tanks will have a welded 90 degree mounting plate to both sides of the tank and bolt directly to the frame.

I'm not fond of the 90 degree mounts because I see aluminum welds as being susceptible to fatigue cracking as the frame has slight movement and the tank doesn't want to twist along with the frame.

I'm going with 4 mounting points, using rubber donuts between the tank mounts and the new mounting points from the frame.

The pic below shows the steps to fit the aluminum tank mounts together and the other pic is the mounting tabs that mount to the frame.

Fortunately the frame already has factory holes to bolt my mounts to. I am also always looking to make my life easier so when ever possible,, I will weld the nuts in place, makes everything so much easier later.

[dsraven]

Try to make it easy to get the tank out as well. Without taking the box off the truck. I cant tell you how many times I have cussed out an engineer or manufacturer for putting stuff together in a way that looks good on paper but makes it really labour intensive for the guy fixing it.

[Stepside Jim]

We'll take care of the ease of install today, and a little more of ventilation.

I am fortunate to work with a lift. One of the first tools I bought was a transmission jack. Along with the transmission jack I ordered a kit to use the transmission jack as a Gas tank removal and install unit.

First pic, more of ventilation. I figured I'd use braided hose to continue the vent, problem is, the braided hose will droop without support. I didn't think drilling hoses in the tank and using self tapping screws to use clamps wound be wise.

This is the time to think ahead and foresee and solve the simple issues. I used 1 inch I.D. aluminum tube, cut in half, shaped to fit the hose diameter, weld to the tank guaranteeing an upward angle. The vent will continue to the inside of the dr. side wheel well, I'll get that later.

Second pic, no bottom welded in place yet. I wanted to get the tank in place and mount it, then lower the truck and see how it looks concerning distance from the ground and how much it hangs down in sight. Strange enough, 1 inch removed from the bottom made a big difference in seeing the tank from the sides and from the rear. With this 1 inch removed I still stayed just over 20 gallons of which is my goal.

Second pic, easy install, raise tank up, run mounting bolts through the rubber bushings and mounts. No nuts to hold onto since they are welded to the frame mounting tabs.