Napco questions

[Hblee]

So my plans for a BBC powered 57 may change. My ex BIL came across a basket case 57 3100 Napco outside of Monroe, LA. Before I drive up there to take a look is there anything special I should know? Like are parts hard to find? I'm sure it will need the front and rear axles gone through plus the transfer case. I'm thinking I will just swap the Napco stuff on to my frame since it is really nice. I would be using my original 265 and a friend has an SM420. Thoughts?

[1project2many]

NAPCO drivetrains are always cool imo. But switching to the old axles means moving your truck from driver to collector truck imo. The gear ratios are not highway friendly (usually 4.56:1) and if something breaks the replacement parts are difficult to obtain. True, these axles are pretty tough but they do still need repair and maintenance to keep running.

If a frequent use 4X4 is in the plan then I'd suggest using parts from a more modern drivetrain.

[Purcell69]

If it is a true NAPCO, "NAPCO" will be cast into the axle housings and transfer case. Like was said above, the gearing is not highway friendly. An acquaintance had one that she drove every day to school back in the day. At 45 mph, the motor was wound up pretty tight. As I recall, the gear ratio in the axles was even higher than 4,56, more in the neighborhood of 5.xx so even a tall tire is little help.

A few weeks ago I found a set of axles and transfer case on eBay out of Wisconsin. The seller was looking to get $1500 just for the parts. From a collectable standpoint it works be cool and worth saving from the scrap yard. As a driver, you'd be better off switching to modern axles if you want to build a 4wd

-Joe

[Hblee]

This is all interesting. I think that the 3.90 was the highest ratio offered, 4.57 and 5.14 were optional. I really don't have a clue what gears are in this thing. I read that the 3.38 gearset from Patrick's and others will work but I would end up spending a bundle changing them over plus the other parts. I've also read the NAPCO front axle had some oddball brakes from a Studebaker (??) and some of that stuff is hard to find. Even if the NAPCO stuff had the 3.90 gears the 265 would be wound up going down the road.

I'm not sure yet, I've always liked the NAPCO trucks but I also like BBC, auto, p/s and p/b, a/c and being able to go on a short trip.

Thanks for the replies and advice.

Originally Posted by Purcell69

If it is a true NAPCO, "NAPCO" will be cast into the axle housings and transfer case. Like was said above, the gearing is not highway friendly. An acquaintance had one that she drove every day to school back in the day. At 45 mph, the motor was wound up pretty tight. As I recall, the gear ratio in the axles was even higher than 4,56, more in the neighborhood of 5.xx so even a tall tire is little help.

A few weeks ago I found a set of axles and transfer case on eBay out of Wisconsin. The seller was looking to get $1500 just for the parts. From a collectable standpoint it works be cool and worth saving from the scrap yard. As a driver, you'd be better off switching to modern axles if you want to build a 4wd

-Joe

[OrrieG]

Everything you want to know about NAPCO trucks.

http://napco4x4.org/

"Modern" 4x4 usually have a 3.73 ration with autos, 4.11 with standard transmissions. 265 will rev a lot more than a stock 350, I ran a 283 .30 over from 85 to 2000 with no issues at highway speeds (3.73 rear). In addition to the cast logo the transfer is divorced and way back, so they have a long front driveline and in/out lever. May or may not have the fender trim it was shipped in the box and up to the customer to install. Should have the shift pattern instructions on the dash or inside the glove box lid, sometimes they stuck them on the cab roof above the windshield too. Worth saving but PITA if they break.

[Purcell69]

Originally Posted by Hblee

I'm not sure yet, I've always liked the NAPCO trucks but I also like BBC, auto, p/s and p/b, a/c and being able to go on a short trip.

Thanks for the replies and advice.

I know what you mean about the BBC. I built one and installed it in my wife's 1978 C10. There is no describing the smile on her face the first time she got in to the throttle. At one point, I had the parts to put a BBC in my build, but when fuel prices went crazy after 9/11, I sold off all my big block stuff and rebuilt the 350 that came out of her C10 for use in the 57. Now it's sitting on a dolly and I have a Magnum 360 ready to go in.

The 454 is a fun motor and can take a lot of revs, but it gets pretty monotonous listening to it going down the highway with a set of 3.73 gears and no overdrive. I finally swapped out her rear end for a 3.07 geared rear. The motor had more than enough torque to pull those gears and crazy wheel spin if you wanted to "put on a show", lol.

-Joe

[bajabob]

Hblee
You asked for opinions so here is mine.

I love the hotrod/ratrod scene and will build one in the future but I wanted something different for my long bed. I found the Napco stuff and you just don't see it out there that much. I like the lifted skinny tire look and my truck is really just going to be a surfboard hauler to the beach and back so I am not really worried about speed. I wouldn't mind doing some jeep trails in the local mountains and maybe out in the Az desert but obviously no pre running!!! lol !!!

It is a little more challenging to find the Napco stuff but it is out there or can be machined. I would score the Napco especially if its original (check to see if the transfer case brackets and shifter brackets are riveted to the frame which should indicate a factory install, although it would be easy I have been told to reproduce the rivets and make it look factory???).

bb

[Hblee]

So I've exchanged a few emails with the guy. It has 3.90 gears and allegedly all of the NAPCO running gear is in really good shape. I had intended to take a ride up there on Saturday but it looks like it will be after Thanksgiving before I can go.

He says it's a real RPO 690 factory built 4wd. We'll see. If I can get it right I think I'll go ahead and pick it up.

[Purcell69]

Best of luck. It is good that you are looking at it first hand. I saw someone advertising a "NAPCO" last night (I can't remember where), all original, etc. it had a 350 V8 and non-divorced mount transfer case. Clearly not an original NAPCO for 1957.

-Joe

[1project2many]

He says it's a real RPO 690 factory built 4wd.

Well, Napco or not it sounds like he gets credit for doing his reasearch. Not too many folks know the correct RPO.

[Purcell69]

Originally Posted by 1project2many

Well, Napco or not it sounds like he gets credit for doing his reasearch. Not too many folks know the correct RPO.

Very true. That is a good sign for sure.

Here's spare parts for one, or a conversion kit:

http://albuquerque.craigslist.org/pts/5288015474.html


-Joe

[Hblee]

Dang, I'm gonna need that drive shaft that runs from the SM420 to the transfer case.

Originally Posted by Purcell69

Very true. That is a good sign for sure.

Here's spare parts for one, or a conversion kit:

http://albuquerque.craigslist.org/pts/5288015474.html


-Joe

[OrrieG]

Get a sm420 output piece or complete drive line. Measure the distance from the output piece midway in its travel to the centerline of the transfer universal joint. Take the measurement, output piece and transfer case to a driveline shop and they can make one for you for less than the price of finding a "correct" one. If you have the complete drive line they will be able to figure out the transfer case universal joint, there are ones made for adapting different sizes.

[bajabob]

I have had several driveshafts "made" not an issue at all. Getting all the right parts way important!! I.e. Shifter brackets and linkage!!! Correct axles and transfer case. If you can find a tc with the pto for a winch!!! That would be way cool!!!
Bb

[Hblee]

Thanks for the advice, fellas. I finished cleaning my dad's garage out last week and found a SM465 yoke, a T400 yoke and I have a couple of smaller yokes for a Muncie and the original 3 speed. It's been a while since I've had an SM420 so I'm not even sure what type of slip yoke it uses but I bet I can round one up. I have a couple of driveshafts laying around so I should be able to come up with something that will work.

I wanted to go look at the stuff last weekend but the guy was out of town for the week of Thanksgiving. He then wanted me to come this weekend but I can't, my daughters are both down for Thanksgiving. We are going to try again next weekend, I might even try to take a day off during the week for a road trip.

[Hblee]

Well after a quick search on Google and I found out that an SM420 doesn't use a slip yoke. All of the parts seem to be available from quite a few places.

Originally Posted by Hblee

Thanks for the advice, fellas. I finished cleaning my dad's garage out last week and found a SM465 yoke, a T400 yoke and I have a couple of smaller yokes for a Muncie and the original 3 speed. It's been a while since I've had an SM420 so I'm not even sure what type of slip yoke it uses but I bet I can round one up. I have a couple of driveshafts laying around so I should be able to come up with something that will work.

I wanted to go look at the stuff last weekend but the guy was out of town for the week of Thanksgiving. He then wanted me to come this weekend but I can't, my daughters are both down for Thanksgiving. We are going to try again next weekend, I might even try to take a day off during the week for a road trip.

[G&R's57GMC]

My '57 GMC NAPCO was factory installed . It has 3.90 gears. With the stock tires it was a screamer at 60 mph so I installed the tires from my Avalanche that are 32" diameter on 16x7 wheels. Now it will cruise at 65 mph all day without breaking a sweat.

[Hblee]

So I finally got to go look at some NAPCO stuff that a guy in the Texas Hill Country had for sale on Craigslist in Austin. I loaded up a friend's trailer and had a nice road trip yesterday. This guy and his dad have really got the Task Force trucks. His dad said at one time they had over 200, but had sold quite a few and were trying to get down to 60 or 70. They are on a 400 acre place so they have plenty of room. There was a sea of old trucks. I counted at least 5 Cameos and they were a dozen or so Suburbans, and a panel truck or two. There probably 20 big window cabs. Most of the trucks that were lined up are pretty rough, lots of rust and most would be considered basket cases IMO.

They had 4-5 NAPCO trucks and a NAPCO Suburban plus a 57 and 58 rolling chassis. I wanted the 57 but the 58 was so much nicer, plus it had 16" wheels on it. I ended up getting it and got everything but the short driveshaft to the transfer case and the linkage from the shifter to the transfer case. He only had one set and didn't want to part with it. Honestly it didn't look like much, I think I can make something pretty close with an old shifter rod, some flat stock, clevis pins and a few other parts.

So I think I did all right, I had to pay a little more because of the 16" wheels but at least I won't have to be searching for a set of them.

This was my dad's truck and he liked original stuff, so in honor of him I'm going to restore it as close as possible to how a NAPCO would have been new. I wish he was still around the help work on it.

I dropped the frame off last night at a friend's repair shop. He's going to take it all apart and then I'll decide how deep I need to get into the front and rear diffs, whether they need a total rebuild or just some bearings and seals and a new paint job and new brakes. The transfer case was just rebuilt (allegedly) so I"m hoping it won't need anything but some paint squirted on.

I'll post some pics when I get it presentable.

[OrrieG]

58 frame is easy to use for 57 only difference is the front frame is extended about 2.5 -3" because of the longer 58-59 fenders and extended grille.

[Hblee]

OrrieG, my 57 frame is pristine, smooth, no pits, the VIN and all of the little stampings are there. I'll be swapping the 58 parts onto my frame, I'll just need the usual longer brake hoses, parking brake cables, etc. The 58 frame still has the original spiral shocks but there have to be some shocks that will work. The driveshafts I got are from a swb truck.

The blocks that are on the rear are different from the other NAPCO trucks I looked at. These have a protrusion sticking out similar to a small anvil that would contact the bump stop. The other lift blocks were square.

So it's time to get started on the 265 and find an SM 420. I want to have the frame done this winter.

Originally Posted by OrrieG

58 frame is easy to use for 57 only difference is the front frame is extended about 2.5 -3" because of the longer 58-59 fenders and extended grille.

[1project2many]

The "bump stop" blocks are something I've seen on other NAPCO trucks. Can't tell you if they're original, though.

[Hblee]

He had 3 original line built NAPCO trucks, the frame I bought was the only one that had these bump stops as part of the lifting block. This frame also had an extra set of leaf springs on top of the lower stack. The extra stack was also 5 leaves and shorter and the u-bolts looked to be about 3" longer. It all looked original and not added on but who knows when you're dealing with stuff that is over 50 years old.

The frame I got is from a GMC, the other 2 were Chevys. I'm not sure if they were configured different from a Chevy but it would appear that way?? I'm a NAPCO newbie and I have a lot to learn and figure out. I found more good info from the Stovebolt site than I did the Napco 4x4 owners website.

Originally Posted by 1project2many

The "bump stop" blocks are something I've seen on other NAPCO trucks. Can't tell you if they're original, though.