Start of my 66 C20 Build

[66_C20]

So the truck itself is a 1966 C20 longbed. The story behind it... as far back as I know of, the truck belonged to my grandfather, we had a family farm where the truck has been parked ever since I can remember. My grandad got pretty sick when I was about 5 or 6 years old (29 now) so my parents along with my sister and I moved close to them to help out on the farm. So as far back as I can remember, I’ve never seen that truck move from the side of the barn up until about two weeks ago. Very long time. When my grandfather passed away, he left the truck to my dad who always intended to fix it up but never got around to it and when he passed away back in 2015, I inherited it. So I’m making it a priority to get the truck fixed up.

It’s going to be a fairly slow process since I’m in the military stationed in NC and the truck is back home in Alabama. However, I did make it home for these past two weeks and got a little work done on it. I don’t really have the room at my home in NC for another vehicle, I already have a Jeep, Camaro, and motorcycle so I’ll be taking a trip home probably once a month for about 4ish days to work on it little by little.

The overall intent for the truck is to just keep it a nice looking cruiser that I can drive to work a few times a week. It’s not going to be crazy custom or bagged out but it’s not going to be kept all original either although I would like to keep it as C20ish as I can. The truck is a three on the tree which I want to keep and I have a Chevy big block I’d like to put in it. Don’t know if those will play nice together. I’d like to add power steering, power brakes, and A/C as well. As for the interior, I just want to restore it and get it looking nice, keep the old bench seat and have it recovered to look nice, and the exterior will just have the sheet metal fixed and a nice coat of paint sprayed down. Finally for the stance, I would like to drop it some, how much though I have no idea but I would like to put a set of Detroit Steel Wheels 20” smoothies on it also (and keep the 8 lug wheel pattern).

Below are some pictures of the rust bucket and I mean it, she’s pretty rough. I’ll also add pictures of the progress over the past two weeks as well as plans and questions for the next trip down here in a few weeks to work on it.

[66_C20]

Getting the truck moved proved to be much more difficult than anticipated. The front tires were flat and wouldn’t hold air which was no big surprise but the back tires were still full of air. Problem was we didn’t find out until we tried to move it that the rear end is froze up so none of the tires will turn. Which, the tag on the truck is from 1992 so it hasn’t moved from its spot in at least 26 years if not longer. The buddy we had helping us didn’t have a winch on his car trailer so we called in a rollback to get it to the shop and then came up with some interesting methods to get her into the shop to start pulling the motor out.

[66_C20]

Then me and my buddy started working on the big block. It’s a 454 with .040 over pistons and a standard crank which makes it about a 462. Cast iron heads, oversized intake and exhaust valves, aluminum intake and a 750 cfm double pumper on top with some Doug’s shorty headers on the bottom. We took it down to the bare block, put new freeze plugs in it, new cam and cam bearings, balanced the full rotating assembly with a new balancer and flywheel, and put it all back together.

Like I mentioned earlier I plan on keeping the three on the tree so I cleaned the mess out of the trans as much as possible, bought a new clutch assembly for it and went from a 10” to a 12” clutch and also put a new pilot bushing and throw out bearing in it. Good bit of work done but still a good bit of work to go still.

[66_C20]

And here’s the big block bolted down into its new home. We had to do some “massaging” of the firewall to get clearance for the valve covers and we also ended up cutting the center section of the radiator support bracket as well to make it easier since we put it in with the trans mated to it. But it will obviously get welded back up once it’s done.





We got the starter, fuel pump, and distributor put in along with the plugs and plug wires ran which I didn’t get a picture of due to an issue with the exhaust manifolds. We didn’t get the headers delivered before I had to leave so we were going to just use stock manifolds to get it fired up but the problem was clearance. So we flipped them upside down but then couldn’t get the plug wires boots on some of the plugs. So we were at a standstill.

[66_C20]

So here are some parts for the next trip coming up in a few weeks. Below are the headers along with a complete set of parts to rebuild the rear brakes, minus a few things that were back ordered.





Which brings up my first round of questions:

1) I have zero confidence that these headers are going to work after seeing all the clearance issues we ran into with the manifolds. They were hitting the motor mount perches on one side and the inner fender well on the other which is why we flipped them. Then we couldn’t get the plug wires on the plugs. So I’m not really sure what the fix for that would be and then that’s not even considering the clutch linkage which will also likely be an issue. Which could possibly be fixed by making it a hydraulic clutch instead?

2) I’d also like to start looking at converting the front brakes to power disk brakes which I’ve seen a sticky around here somewhere with links in it for different year models that would convert over. Only thing is, I’d like to keep the truck an 8 lug as crazy as that probably sounds.

3) I also need a radiator for this bad boy. I came across one on summit that was a 3 row made by frostbite cooling for like $300 (PN-FB118). I plan on putting an electric fan on it as well, I just want to know if that would be enough as well as if that radiator would be an easy drop in deal.

4) Lastly, I know these 3 speed column transmissions need some “freshening up” and whatnot but don’t really know the little things to do, adjust, tighten up, clean, lube, and lord knows whatever else to make this thing shift nice and smooth and reliable.

[Captainfab]

Welcome to the forum and thanks for your service

Making the original clutch linkage work with a big block in these trucks is next to impossible. Plus with those headers it definitely is not going to happen. I do make a booster bracket with the hydraulic clutch conversion. You will have to source the clutch slave conversion from someone like Novak Adapters.

http://www.67-72chevytrucks.com/vboa...d.php?t=651200

https://www.novak-adapt.com/catalog/...hcr3/kit-hcrc/

To convert a '63-'66 C20 to disc brakes isn't much different than with a C10 except that you must change the entire front suspension including the crossmember. This is much easier with the engine out.

Before you get too carried away with new parts on that differential, I would check to see what gears it has. Most of the Eaton HO52/72's had 4.57 gears. Those are not highway friendly and not what you really need behind a big block.


I don't know if that radiator will cool that big block. It will depend on what you do for a fan and a shroud. I would suggest one of the many aftermarket radiators made specifically to fit the '63-'66 trucks. I like this one.

https://www.ebay.com/itm/1963-1964-1...19.m1438.l2649

But with that radiator you will need the correct upper and lower saddles versus what the 6cyl used unless it had the HD cooling radiator.

[66_C20]

Originally Posted by Captainfab

Welcome to the forum and thanks for your service

Making the original clutch linkage work with a big block in these trucks is next to impossible. Plus with those headers it definitely is not going to happen. I do make a booster bracket with the hydraulic clutch conversion. You will have to source the clutch slave conversion from someone like Novak Adapters.

http://www.67-72chevytrucks.com/vboa...d.php?t=651200

https://www.novak-adapt.com/catalog/...hcr3/kit-hcrc/

To convert a '63-'66 C20 to disc brakes isn't much different than with a C10 except that you must change the entire front suspension including the crossmember. This is much easier with the engine out.

Before you get too carried away with new parts on that differential, I would check to see what gears it has. Most of the Eaton HO52/72's had 4.57 gears. Those are not highway friendly and not what you really need behind a big block.


I don't know if that radiator will cool that big block. It will depend on what you do for a fan and a shroud. I would suggest one of the many aftermarket radiators made specifically to fit the '63-'66 trucks. I like this one.

https://www.ebay.com/itm/1963-1964-1...19.m1438.l2649

But with that radiator you will need the correct upper and lower saddles versus what the 6cyl used unless it had the HD cooling radiator.

Thank you for your reply, I really appreciate the help and advice. I’m sending you a PM for a little more in-depth discussion on the hydraulic clutch kit.

As for the radiator you linked, I do like that one as well and I definitely need to keep this bad boy cool. As for a fan and shroud, I was thinking of just going with an aluminum shroud and an electric fan such as this :

https://www.jegs.com/i/Champion-Cool...FS284/10002/-1

https://www.jegs.com/i/Champion-Cool...CFK16/10002/-1

As for the upper and lower saddles, any insight as to where I can get them and how to know I’m getting the correct ones for the radiator that you linked?

[Captainfab]

You can also buy that same radiator with a shroud and electric fan.

https://www.ebay.com/itm/1963-1964-1....c100005.m1851

I'm not sure if that radiator has the same size tanks as the 3 row copper/brass radiator or if they are the same as the 4 row core. Either way, if you need the saddles, you will have to find a good used set. I may have a top hold down if you need one.

[66_C20]

Originally Posted by Captainfab

You can also buy that same radiator with a shroud and electric fan.

https://www.ebay.com/itm/1963-1964-1....c100005.m1851

I'm not sure if that radiator has the same size tanks as the 3 row copper/brass radiator or if they are the same as the 4 row core. Either way, if you need the saddles, you will have to find a good used set. I may have a top hold down if you need one.

Perfect, thanks for that link. Makes it much easier that it all comes as a package deal. So I guess I’ll just set it in and see what it looks like but it sounds like I may end up needing saddles from a C10/C20 (this same body style) that came with a V8 and HD radiator. Am I understanding that correctly?

[66WideinOhio]

Hello 66_C20, I was wondering what motor mounts you use on your engine. the small block original mounts or some thing different? I plan on putting a 454 in my 66 also.
Thanks

[66_C20]

Originally Posted by 66WideinOhio

Hello 66_C20, I was wondering what motor mounts you use on your engine. the small block original mounts or some thing different? I plan on putting a 454 in my 66 also.
Thanks

So that straight 6 that is pictured earlier in the thread... I literally just pulled the motor mount pads off of it and low and behold they bolted right up to the big block and the stock motor mount perches. I’m assuming GM is really simple and rarely ever change things like that.

[66WideinOhio]

Thank You for the reply. I'll be watching this one

[66_C20]

So I came home for thanksgiving and did some work on the truck. The plan was to hopefully get the headers on it along with the carb and start it up and then I also had parts to rebuild the rear drum brakes as well. As anyone can expect, there were some successes and some setbacks. The headers didn’t have near enough clearance to fit but we really wanted to start it up and hear it idle so that’s what we did. Without headers or a cooling system, we only let it idle and even then we didn’t run it for more than 15 seconds at a time or so.

https://m.youtube.com/watch?v=lJ-3Vw_YiK4

So next we figured we’d get the rear brakes rebuilt but when we started digging into the boxes and then looking at what shape the brakes were in, we needed to order a few more parts. We ended up just tearing down the brakes and waiting to rebuild them until the rest of the hardware comes in.

The plan from here is to move the engine forward about an inch and a half, change the trans to a turbo 400 and build a transmission crossmember for it and mount it a little farther back than where it currently is. That should hopefully give more room for the headers to fit without forcing me into a custom set and make routing the rest of the exhaust a little easier as well.

Next month, I intend on getting the headers on it, get the radiator in it and rebuild those rear brakes. I also have the entire front end from a square body Chevy so I also intend on rebuilding it and transplanting it into the truck converting the front to power discs as well as power steering. Then lastly, swapping the 3OTT for the turbo 400 with its new crossmember. We’ll see how much of that actually gets accomplished.

[pdxhall]

Welcome. It's great to see you working on a truck that has been in your family for so long. Nice project so far.

[66_C20]

Originally Posted by pdxhall

Welcome. It's great to see you working on a truck that has been in your family for so long. Nice project so far.

Thank you sir, she’s coming along slowly. I’ll have some more updates in a few weeks, hopefully with headers on it and power disc brakes.

[66_C20]

Got quite a bit more work done on the old truck while I was home for the holidays. There are about to be a lot of pictures coming, fair warning. First thing to do would be to get the front end I bought ready to put under the truck. Front end is out of an ‘86 C20 which will give me disc brakes and the better suspension in general as well. Took the front end all apart, cleaned everything really well, replaced what needed replacing, had the rotors turned, painted everything and then put it all back together.

[66_C20]

While working on the front end at the machine shop I worked at before joining the Army, I was also working on getting the emergency brake system replaced and the rear brakes finished up on the truck. Didn’t get pictures of either of those projects unfortunately but I kept the rear brakes as drums and just replaced every single associated component with new items and the same goes for the emergency brake, minus the handle itself inside the cab.

Also didn’t get any pictures of the process of removing the factory front end out of the truck but we basically just lit the torch and did our thing. Yanked the motor and transmission out, removed the entire front crossmember to include the steering linkages, steering box, and the transmission crossmember as well.

[66_C20]

Then came the fun part... putting the ‘86 front end in her new home. As you can see below, we basically rolled the front end underneath the truck and then lowered the truck down onto it, lining everything up as best we could. We found it easiest to get the bottom six bolts lined up and bolted in first and then work on the four on each side. As I found in researching prior to taking the project on, one bolt hole on each side has to opened up some and then another one on each side had to be drilled. Other than that though, it wasn’t too bad.

[66_C20]

To back things up just a bit, before installing the new front end, I went ahead and installed the steering box off the same donor vehicle that the front end came off of (goal is to give the truck power disc brakes as well as power steering). Reasoning behind that was as simple as, it would be easier to do with everything out of the way. I used the adapter plate from Captain Fab who I would like to give a big thank you to. Throughout just this round of modifications, I used his power steering adapter plate, power brake booster bracket, and heater blockoff plates and I must say his products are top notch, his customer service and communication is top notch, and his advice and willingness to genuinely help is fantastic. I very much appreciated it.

So after getting the steering box mounted in its new home, I also decided to go ahead and test fit the new tubular transmission crossmember to see how it looks. I ordered a package deal from Western Chassis for big block tubular perches with motor mounts along with the tubular transmission crossmember and transmission mount. It fits perfectly and I couldn’t be happier with it.

[66_C20]

When I started this project, my plan was to keep the three speed on the column. I loved it and really really wanted to keep it but as the project progressed, it was just going to be a huge pain in the neck between clearance issues with the big block, with headers, the bell housing crossmember, linkages, and so on. So I opted to go with a TH400 instead, which is why the tubular trans crossmember was added to the parts list. This also meant that I needed a new steering column since it would be a column shifted automatic. So again, I put in an order with Western Chassis for a tilt column which I like quite a bit. Took a little creativity to get that project all worked out but I think we got it handled. The two biggest issues were the fact that the column had no mounting holes so we had to test fit it in the truck, mark where we wanted it, drill holes and tap them. Ended up having to do that twice unfortunately. Then the end of the column itself had to be attached to the end of the intermediate steering shaft somehow so that led to us drilling a hole in the end of the column and then putting a bolt and locknut through it all to connect it.

Also went ahead and mounted the power brake booster bracket which was very easy. I have the booster and master cylinder but didn’t get a chance to mount those items. Bought a brand new booster for a late model S10 and a master cylinder for an ‘86 C20 from O’ Reilly’s. I can’t remember the exact year of the booster but it was on the list Captain Fab sends with his bracket of applicable boosters. Went with the smallest one per his recommendation considering the big block and mitigating potential clearance issues.

[66_C20]

Another little associated project I failed to take pictures of was attaching the steering linkages on the new front end. It really wasn’t too difficult, especially since I mounted to steering box prior to. We just attached the pitman arm to the steering box, attached the tie rods and then used two levels, one on the frame rails and one on the center linkage. The goal was to get the level on the center link equal to where the level was on the frame rails. Measured the distance of the center link from the crossmember on each side where the tie rods mount to the center link, clamped the idler arm to the frame rail and drilled the holes for it. The passenger side wheel is turned out just a hair with the driver side straight but that should be an easy fix by adjusting that tie rod. This bad boy will need an alignment anyway.

With that all worked out, it was time to put the 454 and TH400 into the truck and get everything bolted down with the new mounts. Pretty much everything had to be drilled for new holes. We used the tubular perches and basically placed them in a happy medium between the two mounting holes in the frame rails from the factory. This moved everything forward about an inch and quarter/half from where we had it with the original perches which gave us more clearance for the valve covers, distributor and headers without getting all up into the radiator at the same time. Which meant new holes had to be drilled for the transmission crossmember as well. No big deal, I’m well-versed in the use of a grinder and a drill at this point.









Was even able to get the headers bolted on after a little persuasion with a torch and big ol hammer.





Oil changes are going to be interesting with the way that header hugs the oil filter on the driver side



And that’s how she sits. Still need to get the booster and master cylinder mounted, all new brake lines front and rear need to be made and then get a transmission and throttle linkage for it. I’m probably going to swap an electric water pump on it for a little freed up horsepower as well as front end clearance with the radiator. Then mount and plumb the radiator, wire it up, and throw a driveshaft in it and maybe I’ll be able to take it for a drive for the first time.