New to the Group
 

Good morning all. Bought my 65 GMC from a family friend in NM and hauled here to CA. I was surprised to find how rare the V6 305 was and wow are the parts few and far between. So far we have cleaned the fuel lines and tank, replaced all the rubber fuel hoses. Changed the oil and filter and put a new battery in. Fired right up! There is some fuel seeping from the carb and fuel pump as well as fuel spitting from the vent hole. I'd like to go slow and fix things that we find wrong along the way. Eventually get it as close to full restore as possible. Love the fact it has a 4 speed manual trans, can't wait to tech the wife to drive it.

Re: New to the Group
 

Welcome to the Forum JCHef!

Nice looking fenderside you have and glad to hear you will keep the V6!
:welldone:


More photos when you are able :coolphotos:

Re: New to the Group
 

I'd like to "second" Funky's comments. We're all glad you're keeping the V6. Way too many V6s get pulled, scrapped, and replaced with small block Chevy engines. Many parts for the V6 are easier to find than you might think. If you get stumped looking for something in particular, just let us know.

Keep us informed on your progress!

Re: New to the Group
 

What is opinion of Castrol GTX 10w30 conventional oil for use in 1963 305E ?/ Thanks JM

Re: New to the Group
 

Welcome aboard, the help and people here are first class.
Jm, I recently did some research on oil and have found I like and use Shell Rotella T4 --10W30 is ok. I like the T4 because it has enough zinc in it. Oils for the most part are devoid of zinc these days because most camshafts have a roller follower, as you know the GMC mighty V6 has a flat tappet mechanical cam so zinc is what you are required to have to sustain good long life in the camshaft arena. One could argue that it is sufficient with having just the cam in a constant oil bath like this engine has but for 16 bucks a gallon for the T4 why risk it. I would stay with dino oil and away from synthetics unless you have new seals. My humble opinion only.
You could also stay with your favorite brand and buy a zinc oil additive too, you have options.

Steve

Re: New to the Group
 

I know this goes against the recomendations of most, but unless you live in a cold climate for at least 6 months of the year, I recommend a single weight series 3 diesel engine oil preferably SAE 40 for several reasons. Zinc content, which has previously mentioned, is one. Second, I recommend single weight oils for the reason that a single weight oil gives more cushion than a "mulit-viscosity" engine oil. Engine oils do not get thicker when the oil temprature rises. If you want to see what your multi-viscosity oil looks like at 200 deg. F., mix one quart of your oil with one quart K-1 Kerosene. That oil is super thin, and has no cushion. Years ago, a Standard Oil distributor (now called Chevron) told me what the mulit-viscosity rating means. The first number (using 10w-30 as an example) is the base of the oil. In a 10w-30 oil, the 10w is a SAE10 winter grade oil (approx SAE 8) with the additive package that gives the oil the surface tension of a SAE 30 oil without the body or cushion of the SAE 30 oil. Our V6 engines came from the factory with more verticle oil clearance than the typical passenger car engine. As a dealer fix for the "covey of quails" noise upon initial start up, my dad would install .002 U.S. rod bearings in a customer's engine to stop the noise created by the verticle oil clearance of the connecting rod bearings. In giving my reasoning, I only seek to ensure the longevity and protection of the bearings and other moving parts of these engines.

cordially,
Lewis Ellis Matkin, Jr.
Ridge Manor, Florida 33523
1965 1002 GMC V6-305E (soon to be 401M)

Re: New to the Group
 

I also welcome you tho the group!!!

Re: New to the Group
 

Great forum, much needed info,any one know if Castrol GTX 10w30 conventional has adequate ZINC ? this oil was highly recommended, however this is my 1st change 1963 GMC 305E 1000

Re: New to the Group
 

probably not. If you use this or any other modern oil, you will have to add a zddp zinc additive with every oil change. Lucas oil company has a great one.

Re: New to the Group
 

Thanks , wont be using Castrol GTX , cant locate dino 20w ?? will use Shell rotella. suggestions for sm420 and rear end ?? jm

Re: New to the Group
 

I use the NAPA 90 weight mineral oil in the sm420 and recommend it for the ones I rebuild for people, I found the newer more slippery 90 weights can make for bad shifts with the 3rd and clutch gear synchros in my opinion. Runs about 15 bucks a gallon takes between 6-6.5 pints.
I dont think you can go wrong with any hypoid gear lube for GL-2 through 5 for the diff. If you have a clutch type limited slip or posi you will need friction modifier.

Steve

Re: New to the Group
 

Use a high quality 85w140 gl-4 gear oil. Personally, i use sae140 gl-4 gear oil, but i know that can be difficult to find.

Re: New to the Group
 

The only problem with using mineral oil in any gear box is the fact that mineral oil won't mix with EP rated lubricant-if any EP lube is introduced into the lube, it will cause a chemical reaction causing the mineral oil to coagulate like blood clotting and causing all the bearings, syncronizers, and bushings to fail. If you use it, make sure that is all that goes in whatever you put it in.

Re: New to the Group
 

Good point Lewis, The 64 will get an R&R in the next couple months, its gear oil looked to be original when I changed it out last month. It was the nastiest I have seen too.

Some of the latest and greatest synthetics lubes I have found are so slick the synchros (especially worn used components) have a hard time meshing the gear as smoothly.

I believe mineral oil was oem until mp gear lube came along it was gl-1. When that happened must of been into the 60s some time.
I believe some sm420s found there way into many new vehicles after that into the 80s maybe abroad.

Thanks for your point.

Re: New to the Group
 

Sooooo is Shell Rotella T4 the best oil to use in a 305E gas motor???

Re: New to the Group
 

it depends on your climate. If you are in a climate that averages 32 degrees F, or below 6 months of the year, yes if you use 15w40 T4.

Re: New to the Group
 

Not that cold in southern New Mexico, 3 months at night are cold . Just looking for the best oil for 305E V6. Thanks for input, any other suggestions?? JM

Re: New to the Group
 

I would use the Shell T1 SAE-40 or something with similar ratings.

Re: New to the Group
 

Thanks Lewis ,will check out Shell T1 40W, Have a great Sunday. JM

Re: New to the Group
 

I'm sure we all have our own favorite oil for our V6 engines, JM. This topic seems to come up every couple of years. My favorite is Amsoil which I've been using in all my vehicles successfully since 1974. Amsoil has developed dozens of different engine oils since then, and many other lubricant products as well. My favorite for our old V6 engines is a high zinc oil available as a 10W30 or a 20W50. See https://www.amsoil.com/shop/by-produ...?code=ZRTQT-EA.

Re: New to the Group
 

As far as oil is concerned the diesel oil up until a couple of years ago was rated CJ and contained enough zinc for flat tappet cams. The newer CK rated diesel oil has most of the zinc removed for the emissions systems on the newer diesels. I was using Chevron Delo and after a conversation with their lab guy have mow switched to Amzoil Z Rod which is the older motor,flat tappet oil. My 2cents worth. Dave

Re: New to the Group
 

Thanks guys, appreciate input , trying to keep my 63 in top shape, Will be adding pictures soon ,I sure like my GMC. jm

Re: New to the Group
 

I use Valvoline VR-1 10W-30 racing oil. It's high zinc.

Re: New to the Group
 

Hey Bob thanks for comment on Valvoline VR1 10w30 , just ordered a case. I like that it is conventional oil and high zinc.JM