1966 GMC 351E Rare?

[duallyjams]

I seen your GMC on craigslist if you were closer I would have bought it already.

[BobS]

Wiring Diagrams, the first covers 65-66 1000-2500:




Wiring for RPOs:




They are also located on my Webshots page under "Wiring Diagrams".

http://community.webshots.com/user/124377n

PM me your e-mail address and I'll send you the JPEGs, it will be easier to read them and you can print them off that way.

Bob

[factorystock]

Many people don't realize many 66 GMC's had new options that 60-65 GMC never had. Besides new interior packages and bigger engine,GMC actually offered 2 granny 4 speeds in 1966. The new NP435GA ( reverse on right and down) was offered as an option in '66 GMC's in addition to the GM SM 420, which is found on both 60- 66 Chevy and GMC pickups. Chevy did not offer the NP435GA trans like GMC did in 1966 as a RPO.GMC offered this trans on both inline and V6's engines.Does anyone know if the NP435GA a direct bolt in a 64-66 Chevy if you want to replace your old noisy SM 420? Isnt the 66 GMC inline bellhousing the same as a 64-66 Chevy bellhousings? Any input, especially from BobS, would be appreciated?

[cbrwags]

I have been working on the gmc, The weather looks great, so I can be outside: I dont want to melt... I got it running ok, it has a knock when rpm's go up? It sounds like the sound is from the water pump could it be a thrust sleeve/bearing/washer?. I changed the oil and removed the valve covers all looked good 1 rocker was loose and making noise so I just gave it a turn to shut it up. The truck has a cool sound v8 idle and a 4cyl rev, pretty cool sounding engine. Oil was clean and full, I use castrol 5-20 could need thicker oil. I was told the truck had a tick when I got it so I was thinking topend I hope I can get it fixed I will work on it and find some more info on the engine.

[BobS]

The NP-435 will bolt up in place of an SM-420 but keep in mind that the bearing retainer on the 68 and up transmissions is bigger than the 67 and older ones so you would need a bellhousing with the correct sized hole. GMC used the Chevy inline engines starting in 1960 so the bellhousings on those are the same and they also changed in 68. The NP-435GA is a "close-ratio" transmission, it has a 4.56 low compared to 7.06 in the SM-420. The interesting thing about the NP-435GA being offered in '66 is that it was the only year you would have been able to get a close-ratio 4-speed in a 4X4. Once the transmission and transfer case became "married" in 67, you could only get the SM-420 (SM-465 in 68 and later) in a 4X4.

Bob

[BobS]

Could it be the fuel pump? It's toward the top of that same casting where the water pump is.

For a lot more information on the GMC V-6, check out Jolly's site:

http://www.6066gmcguy.org/

Also get signed up for the discussion group, the link is at the top of the page. There is an absolute overload of information on these engines and the trucks they're in.

I've got a couple hundred pounds of manuals for these things so if there's something you can't find, just let me know.

Welcome to the dark side!

Bob

[BobS]

I just re-read your post and saw the oil you're using. I would recommend using a thicker oil. I use Rotella 15W-40 but any heavier duty oil that has a higher zinc content to combat cam wear will work.

Bob

[cbrwags]

Ok sounds good I will listen to it and try to find it. Yeah the oil was what I had in bulk, so I used it I will change it out. I will get signed up for the discussion group. Thanks for all your help. If the chevy dosn't sell I will do both pickups in flat black opoxy primer for me and the wife to cruise, of course I will need to make the grill and trim pink for her. I wish I could draw to see what it would look like I will hunt around google and see if I can find a girl's 65 or 66. She loves her ford lightning, but I think anybody can fall in love with these trucks.

[skoffice]

Really nice truck! Glad to see the V-6's are still around and good runners. I've always liked those things and would love to have nearly original truck like yours one day. Good luck with it!

[cbrwags]

Thanks, I am looking forward to cruising it, I just caught the wife looking on youtube at flat black trucks. I have never done the paint on the pc but giving it a try, I know there are people doing that on the site but I will give a poke at it I have it already in my head so I will be ok, I will see it when its done. I got the inside of the bed painted today, and the floorboards in primer.

[cbrwags]

This is what I did I will keep the chrome trim and grill so just the top and hood will go pink. Picture from Badbowtieguy sorry to paint your truck pink. I only found a swb but it should be ok.

[factorystock]

Thankyou for the reply BobS. So it appears that the '66 GMC NP 435GA is interchangeable with 2WD GM pickups that came with SM 420. Too bad Chevy didn't offer this in their '66 pickups, the close ratio feature seems to better suited for city driving.

[MalibuKasey]

Can you post a pic of the seat??

[markeb01]

If you have a suitable photo of your truck you can submit a photoshop request by using this link, and just explain what you want:

http://67-72chevytrucks.com/vboard/f...splay.php?f=33

[badbowtieguy]

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