C30 Stake beds

[1966C30Stakebed]

First off, thanks for the site and message board I am sure to learn tons of info. I recently purchased a 1966 C30 Stake Bed with what looks like a 283 and an MS420 tranny. I spun the wheels and counted the rotation on the line and it turned 2.5 times so I seem to have the 5.14 gears if you do the math. Not a positraction unit. I am so sad. So the man I bought the truck from says the engine is a GM 300 V8. I researched it and found that GM did make the engine, but I have not checked the numbers on the engine. It has a two barrel, and the previous owner said the firing order is different than the standard 18436572 and have not verified what the order is on the engine. So I have some work to do. She has 16-inch wheels duals and she is screaming at 50 mph. I will put on a tach soon. But she drives like a new truck. The previous owner put all new front end parts, brakes, carb, transmission and some other items that cost him over $6k in labor and parts. Man, she runs great. Two pumps on the gas pedal and pull the choke and is running before she cranks. LOL She ran out of power going up a hill so I will need to check the vacuum advance for proper movement. But as slow as she goes, it's real fun to drive. Heater works great on our -20 degree days out here in western Nebraska in the sand hills of Sioux county. So I can't wait to hear back from some old timers about the engine, and I can't wait to find out more. Oh, the 5.14 rear end will be for sale as I want to drive 65. So I might swap out for a 1970 3.73 positraction if I can find a center unit. I have found an HO52 with 4.11 and that might work just fine. Attached is my 1927 Doctors coupe I want to haul on her back. To see a short video of my new truck, go to: https://www.facebook.com/MichaelJame...34963493409886

Thanks and I look forward to hearing from all of you.

[jtrichard]

300 NEVER heard of such a thing Unless it a combo of other engine parts

And link dont work

[1966C30Stakebed]

Here is what I found on the web.

300[edit]
In 1964, Buick replaced the 215 with an iron-block engine of very similar architecture. The new engine had a bore of 3.750 in (95.3 mm) and a stroke of 3.40 in (86 mm) for a displacement of 300.4 cubic inches (4,923 cc). It retained the aluminum cylinder heads, intake manifold, and accessories of the 215 for a dry weight of 405 lb (184 kg). The 300 was offered in two-barrel form, with 9.0:1 compression, making 210 hp (160 kW) @ 4600 rpm and 310 lb·ft (420 N·m) @ 2400 rpm, and four-barrel form, with 11.0:1 compression, making 250 hp (190 kW) @ 4800 rpm and 335 lb·ft (454 N·m) @ 3000 rpm.
For 1965, the 300 switched to cast-iron heads, raising dry weight to 467 lb (212 kg), still quite light for a V8 engine of its era. The four-barrel option was cancelled for 1966, and the 300 was replaced entirely by the 350 in 1968.
The Apollo 5000 GT sports car, (also sold as the Vetta Ventura) used this engine.
340[edit]
The 340 cu in (5.6 L) 340 was a stroked to 3.85 in (98 mm)) version of the 300. It had a two- or four-barrel carburetor, the two-barrel with 9:1 compression ratio rated at 220 hp (160 kW) at 4000 rpm and 340 lb·ft (460 N·m) at 2400 rpm, and the four barrel with 10.25:1 compression ratio, rated at 260 hp (190 kW) @ 4000 rpm and 365 lb·ft (495 N·m) @ 2800 rpm. It replaced the four-barrel 300 for 1966. It was produced only in 1966 and 1967, with the new Buick 350 taking its place after that.
350[edit]
Buick adopted the popular 350 cu in (5.7 L) size with their final family of V8 engines. Although the Buick design shared the displacement of the Chevrolet Small-Block engine family, the Buick blocks were substantially different and of Buick's own proprietary design.

[jtrichard]

300 BUICK YES whole different animal then a 283 it also wont just bolt in we need pics LOL

[1966C30Stakebed]

Yes, Buick, But the previous owner said GM 300. Was Buick not a branch from GM Division back in the day? Here is a new link to my video of the truck. It will upload in a few hours. https://youtu.be/D_s4SgTcEtE Please give it some time.

[shp4man]

Does it say "Chevrolet" in script on the valve covers?

My experience with previous owner's descriptive information is that sometimes it's not completely correct.

[jtrichard]

YES BUICK was part of GM at that time ... But I have never seen or heard of any 60s Chevy trucks with Buick engine from factory.. Now 50s is a different story ..Late 50s I be-live it was GMC that used a Buick or could have been Oldsmobile (not sure) V8 in some of there trucks..... And from 75 to 76 some Buick's had Chevy 305s and some had Oldsmobile 307s.....Then after the early 80s it has been a free for all of mix and match

[The Rocknrod]

Linky no worky,

[1966C30Stakebed]

Originally Posted by shp4man

Does it say "Chevrolet" in script on the valve covers?

My experience with previous owner's descriptive information is that sometimes it's not completely correct.

Yes, the valve covers do say Cheverlot. And I just published the link. Sorry for the delays.

[1966C30Stakebed]

Originally Posted by The Rocknrod

Linky no worky,

Try this one. https://youtu.be/D_s4SgTcEtE

[1966C30Stakebed]

https://youtu.be/D_s4SgTcEtE The link that works. LOL

[l79m20]

Maybe a 300 hp 327, thats my bet

[1966C30Stakebed]

Originally Posted by l79m20

Maybe a 300 hp 327, thats my bet

I just ID the head mark but have not taken off the cover to view the casting number or date.

https://youtu.be/D_s4SgTcEtE

3795896 1965 283 195, 220 1.72/1.50 59.669 Casting symbol on exterior face of head is single centered pyramid on square block.
CHEVELLESTUFF © All Rights Reserved
3856208 1965 396 375 2.19/1.75 108.989 First square-port Mark IV head. Has spark plug shield boss.
3872702 1966 396 325, 360 2.06/1.72 98.427 All oval-port applications. Has spark plug shield boss. It is debatable as to whether these plug shields were used on the Chevelle but the shields listed in Chevrolet parts books included the Chevelle application.
3873858 1966 396 375 2.19/1.72 108.989 All high performance square-port engine applications. Has spark plug shield boss.
3884520 1966
1967 283
283 195, 220
195 1.72/1.50 60.530 CHEVELLESTUFF © All Rights Reserved

[C10 - C90 Bill]

Looks like a 283, but could be a 327.

Let us know the Engine Code on the Front Pad (Front of Pass Side Head and at the Bottom of it).

[66Submarine]

Nice truck. As everyone else said, the engine seems like a normal 283 (or maybe one of the weaker variants of 327).

"1970 3.73 positraction if I can find a center unit"

Not sure what you mean by that?

Swapping to 4.10's from 5.14's will make your current engine speed at 50MPH occur at 63MPH or so. You might also consider using a later 14 bolt (1973 and later) rear end.

Make sure you don't go too tall and end up lacking power to go up hills in high gear. I personally wouldn't go taller than 4.10...even that isn't giving a 283 all that much leverage if you're trying to haul something and keep up with traffic IMO.

[1966C30Stakebed]

Checked firing order and found to be correct for SBC. Checked the timing and moved it from around 15 degrees to 8. Checked the dwell and it is 50 at idle and 40 at 2500 rpms. I always thought they should be set at 30, but I could not find my dwell tool. But I never checked the dwell after hooking the vacuum line back up. Here is a picture of the front passenger side engine stamp. So I am pretty sure it is a 283 at this time. But I can't wait to hear what comes up from the engine stamp decoder.

[1966C30Stakebed]

Originally Posted by 66Submarine

Nice truck. As everyone else said, the engine seems like a normal 283 (or maybe one of the weaker variants of 327).

"1970 3.73 positraction if I can find a center unit"

Not sure what you mean by that?

Swapping to 4.10's from 5.14's will make your current engine speed at 50MPH occur at 63MPH or so. You might also consider using a later 14 bolt (1973 and later) rear end.

Make sure you don't go too tall and end up lacking power to go up hills in high gear. I personally wouldn't go taller than 4.10...even that isn't giving a 283 all that much leverage if you're trying to haul something and keep up with traffic IMO.

I found a 4.10 GM HO52 drop out. I might install that and run it for a while to see how she hauls. The 283 needs to get pumped up a little with a 4 barrel and headers to make her breath.

[C10 - C90 Bill]

I checked at 3 different places and all 3 are saying a '65 283.

We also cannot tell by the Side Emblems, as someone has taken them off.

Also, the Steering Wheel is not a '66 and is a '65 and earlier style.

The proof will be in your VIN though.

If you post the first part of it, we will be able to decode the Year of it for sure.

[66Submarine]

Originally Posted by 1966C30Stakebed

I found a 4.10 GM HO52 drop out. I might install that and run it for a while to see how she hauls. The 283 needs to get pumped up a little with a 4 barrel and headers to make her breath.

Yeah, try it out. I have 4.10's in my truck behind a mild hot rod 350 and like the combo...also worked fine behind a 307.

[1966C30Stakebed]

Originally Posted by C10 - C90 Bill

I checked at 3 different places and all 3 are saying a '65 283.

We also cannot tell by the Side Emblems, as someone has taken them off.

Also, the Steering Wheel is not a '66 and is a '65 and earlier style.

The proof will be in your VIN though.

If you post the first part of it, we will be able to decode the Year of it for sure.

Here are the VIN # C3696J154XXX and the casting on the engine don't make sense to me either. FO525WA

I am the third owner and the previous over did not know his head from a balloon. LOL He bought the truck to just drive it because he liked it. The first owner was the original owner and since passed on. So there is no help from him.

[C10 - C90 Bill]

Well, it checks out to be a '66.

From my Chevrolet Series 10-20-30 Parts Manual:

C = Conventional Cab w/Gas Engine

36 = 1-Ton (133 Inch WB)

9 = Stake Body

6 = 1966

J = Janesville, WI Plant

[C10 - C90 Bill]

For the Engine Suffix Code:

F = Flint Plant

05 = May

25 = 25th Day

WA = '65 and '66 (283 w/Manual Trans)

Looks like you do have the Original Engine in there. And the Online Sites were Wrong, lol.

They stated the WA was '65 and not '66, but my Parts Books shows '66 as well.

Also, you will notice that the Date above does not include the Year. For that you would need to check the Date Code, but it is on the Back of the Block and hard to see with the Engine still in the truck.

But I would be pretty confident that it is the original '66 Engine you've got there.

[1966C30Stakebed]

Thanks a ton for the information on it being a 283. The hub pulley mounting disk is a dead giveaway as it is not a true harmonic balancer. I have decided to find some 19.5 wheels from a 1970's P30 and run them for I need to buy tires anyhow. Then that way I won't have to deal with changing the rear end as it has brand new brakes, hoses, lines, shoes, drums and it doesn't leak right now. So if it's not broken, why fix it? So does anyone have the current 19.5 on their truck with the 5.14 gears?

[C10 - C90 Bill]

When you find some P30 Wheels check the Lug Holes very carefully. I know at least some of them, if not all, have a Larger Diameter Lug Nut Stud.

I personally believe that idea is not going to work.

Safely anyway.

[66Submarine]

The later wheels will be for 9/16" studs instead of 1/2". (AFAIK) the older 1/2" setups used a flat nut directly on the wheel and the later 9/16" stuff used a clamping plate with conical seats and lugnuts. http://67-72chevytrucks.com/vboard/s...d.php?t=285970

Assuming you have 7.50-16 bias tires on there now (roughly 660 revolutions per mile), a 225/70r19.5 (around 650 revolutions per mile) will be almost the same. The more archaic 8R-19.5 @ 620 revs per mile will make 50MPH be something like 53MPH.