1978 K5 Tribute Restomod (402BBC EFI, 205, 3/4 Ton)

[Conner]

This is awesome, looking forward to following along!

The plan was for a 2” lift with 33’s and to maintain a relatively stock appearance but with a lot of goodies that only those in the K5/squarebody community may know were mods.

I love this direction for the build. There are tons of amazing "wild" builds here, but I'm a huge fan of more "mild", closer to stock-looking builds personally. If my in-progress build is anywhere near as cool as this one is shaping up to be, I will be very happy

 

[ZombieK5]

@ZombieK5 I was a little nervous transporting it but it did fine. I removed the center caster on the rotisserie and strapped it down very well. If your trailer is wide enough securing some blocks to the left and right of the rotisserie casters may be helpful but I didn’t do that.

Interesting. I may give it a try.

How did you get it onto the trailer?

 

[vdamirth]

@ZombieK5 I have a winch on the front of the trailer and used that

 

[folkenheath]

Since you have a racetrack or figure 8 pattern 32 spline 205, use this adapter with your factory one and get a 2001 or newer 2wd 4L80E. They have really long splines that can be cut to the length that you need.

GM 4L80E to TH400 NP205 Adapter/Spacer Kit

This is our 4L80E to TH400 Pilot Adapter/Spacer Kit. CNC Machined in House from 6061-T6 Billet Aluminum. This adapter is used when replacing a TH400 with a 4L80E. 1979-1984 TH400 to Fig.8 NP205 will require a 2wd 4L80E. (Short 2wd 6-1/4" Stick-out requires the Output Shaft to be trimmed 1-1/8")...

northwestfab.com

Good advice, as the 2WD model will also have the output speed sensor the Holley wants to shift correctly in both ranges of the Tcase.

If you want the speedometer to be correct in low range you can still pull the speedo signal from the transfer case, or use a GPS speedo.

ORD also sells a figure 8 NP205/4L80E adaptor, its 1 piece, it's thicker than the 6 bolt round adaptor and doesn't need a spacer.

https://www.offroaddesign.com/4l80e-figure-8-np205-adapter-housing.html

 

[rksjd8420]

Good advice, as the 2WD model will also have the output speed sensor the Holley wants to shift correctly in both ranges of the Tcase.

If you want the speedometer to be correct in low range you can still pull the speedo signal from the transfer case, or use a GPS speedo.

ORD also sells a figure 8 NP205/4L80E adaptor, its 1 piece, it's thicker than the 6 bolt round adaptor and doesn't need a spacer.

https://www.offroaddesign.com/4l80e-figure-8-np205-adapter-housing.html

I think that is the Advanced Adapter one. I bought one years ago and didn’t like the way it fit at all. The transmission mount is in the same place as a TH400 adapter. It hits the transmission pan on the 4L80E. The 1991 4L80E to NP205 adapter has the mount farther back. It is also only 4” thick whereas the 4L80E adapter is 4 and 5/8”.

 

[vdamirth]

@folkenheath I was hoping you’d see this thread eventually. That’s your intake and EFI components on that big block. I’ll definitely need your input when it comes time for exhaust, ignition and setting up the terminator

@rksjd8420 appreciate the feedback again. I do think that adapter you originally suggested is the best option for me. I’ve been searching for a 01+ 4L80e on FBMP

 

[vdamirth]

Got some progress on the body done.

Doors and new rear quarters cleaned up.

Rocker installed on passenger side (driver side had been done by PO and was ok).

Truck bedside gas filler door opening filled. Needs a little dolly work but pretty good. Going to flip the gas door to the driver side and do something a little trick.

 

[vdamirth]

A few questions for you experts:

1) This is an 86 body that I’m going to put a roundeye front clip on. I’m aware the hood hinges are different. I bought a replacement hood, core support and outer and inner fenders for a 78. Do I have to modify the cowl for the older hood? I think the hinges mount to the fenders for round eyes and the firewall/cowl area for the 81+. What do you guys recommend?

2) The dash on this cab is in pretty good shape but I know there are differences in the pads. Is it possible to massage the 86 dash to work with the 73-78 pad or do I need to install a 73-80 metal dash to accept that? Or can I just use a 86 pad? It’s going to be covered with the same vinyl/leather we used for the seats and will have vintage air vents

 

[83ChevyK5Blazer]

Why switch the filler to the drivers side, on directional gas stations there is always a line for drivers fill, but not so many on the other side.

 

[vdamirth]

Why switch the filler to the drivers side, on directional gas stations there is always a line for drivers fill, but not so many on the other side.

I’ve never had an issue with that. Not sure we have directional gas stations in NC. All my vehicles have had drivers side fill for 25 years.

 

[vdamirth]

@ZombieK5 thread about dashes

GMsquarebody thread about dashes

Looks like my best option is to use a 73-78 pad and bezel for the closest look.

Having the straight pad and bezel from the 81+ would be a dead giveaway. The 79-80 had a VIN cutout which a more astute observer may notice but would be ok. Since the price for the 73-78 is the same I’ll start with that unless y’all say different.

Then see how well that can mate to the 86 dash. I may have to fab something near the speaker hole locations to catch the pad back there.

 

[Fastduramax]

Awesome thread VDA, following closely as like you I 'am totally ORD'ing my chassis before/while I install my 572, hopefully I get to study your entire procedure before I start mine this spring haha ! Couple questions, who or what is McBible, fastener supplier ? Pinch nut, same as a Nyloc but all steel with "stamped" detents to lock instead of nylon ? I've had a Fastenal grade 8 bolt bin for years that came with this type lock nuts and while I agree way better than Nylocs I don't believe them to be grade 8 and would never use anything less than grade 8 in a frame... Also are those an updated front spring hanger, I swear I didn't buy them a while back because they didn't clear the stock bumper brackets yet these say they do

 

[Fastduramax]

Ok I answered my own hanger question....

 

[vdamirth]

Ok I answered my own hanger question....

Hey @Fastduramax thanks for chiming in! It’s about to rivet death day soon.

McBible is McMaster-Carr. It’s got just about everything from an industrial standpoint. I used to order from them once a week when I worked in a manufacturing plant for over a decade. The cool thing is there’s a ton of information about fasteners, coatings, components etc.

So when I bought the new front hanger core support from ORD it was an older style. They now have a version that has direct fit bolt holes for the stock bumper brackets. Unfortunately couldn’t swap mine out but it’s pretty simple to make the old ones work with the stock bumper brackets.

 

[Fastduramax]

Dude !!! That website is nothing short of epic ! All my years of wrenching on cars trucks and equipment never heard of it We thought we were kool when we got Fastenal here on Uranus but no more, if I wanna purchase "imported" grade 8 hardware I'll go to Tractor Supply where it's the same shit for half the price... ANYWAY when you starting on that frame and ORD goodies stud ! ORD needs a fancy nickname, I'd say McJesus but some fancy hockey player from that country north of us claimed that one

 

[vdamirth]

Picked up a steering wheel on marketplace. Great price and not too long of a drive. I’m not sure if it’s OEM or Repro but it’s pretty nice and complete. Sellers pics. Any experts on here have an idea how to tell if it’s OEM? I don’t really mind one way or the other, just curious. (Also, from USA1, this looks like a 73-77 and the 78-87 has a different center cap shape)

 

[imiceman44]

Picked up a steering wheel on marketplace. Great price and not too long of a drive. I’m not sure if it’s OEM or Repro but it’s pretty nice and complete. Sellers pics. Any experts on here have an idea how to tell if it’s OEM? I don’t really mind one way or the other, just curious. (Also, from USA1, this looks like a 73-77 and the 78-87 has a different center cap shape)

View attachment 500418

View attachment 500419

View attachment 500420

View attachment 500421

View attachment 500422

Looks like OEM to me

 

[vdamirth]

Hey all, I’ve got a lead on a freshly rebuilt 4L80e 2wd.

I googled the PN on google and it said 99-03. Is this a good version for what we had earlier in this thread?

 

[vdamirth]

Just trying to get input from folks on here. I have to get a wiring harness for the project. There is no factory harness at this point which is fine with me. I am very comfortable and confident with vehicle wiring.

I wanted to see if anyone had real world experience with a full harness. American Autowire, Painless, Jabin Wood, etc.

Just a refresher - 402BBC with Terminator X EFI, 4L80e trans, aftermarket gauges, aftermarket A/C.

I am leaning towards AAW 510706 (Classic Update Kit - 1983-87 Chevy & GMC Truck) however there is a Painless kit which is a few hundred less.

Any advice is appreciated.

 

[centexk5]

Did an aaw on my dads 77 bronco and had no complaints. Easy to follow and well laid out.