The Stovebolt Site Forums The Shop Area Engine Shop 1962 GMC Pickup with a 305 V6 big block

Hi Everyone, so last weekend I purchased a 1962 GMC numbers matching Pickup truck with a 305 V6 from the original California owner. The motor appears to be lockup so my favorite engine shop is going to remove the engine and rebuild it. The question is what's the best place to purchase engine parts?

S

Go to the 6066 site I mentioned to you in your other posts. They have all the info. Warning: Chances are your rebuilder knows nothing about this motor. True that a rebuilder will know about motors BUT, he may get into it, find that he needs to bore it over and need parts and then sends you looking only to find out parts are scarce. The 6066 site will have some and Ebay once in awhile. My advice, find a running 305 V6 and replace. or replace with a Chevy motor. Knowing what I know about these motors, it is VERY odd that it would have one owner and be locked up. You will be draining your wallet soon. I bought a running 305 V6 with a SM420 for $200. Like I said they are boat anchors, but they are the best "truck" motor ever built. Some have gone over 400,000 mi. They don't "lock up" much. EBAY will be your best bet for parts. As I also said in your other post, lot's of torque, no performance. But it is historic and original to the truck. First GM V6. It is an 850 Lb Big Block. 4 1/4 Bore, aluminum pistons. Made the cover of the 1959 Popular Science Mag. Your former story said owner was driving and motor stopped and would not start. You could put some oil in plug holes, let it soak and push it in 4th 10 feet. That has it's risks and rewards. I don't know how much effort was used in try to get it unlocked. But before tearing it down I would be darn sure.

Bartamos, my engine guy said it would take 6 hours to remove and disassembled the motor and see what's wrong = 424.00. should I let him do that or should I just get another 305 GMC or a Chevy Motor? I'm just using this truck as my daily driver....

Scott

Re-read my post I was still thinking and editing.
$424? then work on it? and parts? and put it back together? That's maybe $1500-2500 or more. There is at least one running motor on the 6066 site. $200 in Texas. Those guys are honest to buy from. I was going to put in a Chevy in my 1960 GMC but I found the 305E I mentioned, right in my town, and decided dropping it in was much easier. Why don't you hang loose for a few weeks unless you are in a hurry or are rich. If he bores it you will have to find oversized pistons or rings and all that, gets hairy. If you are not a purest, go Chevy! You can buy a GM waranteed crate motor pretty reasonable now-a-days. It does take some fab work for that frame.

I traded a 62 with the 305 V6 with less than 5k miles on a rebuilt engine to my neighbor for re-rocking my driveway. He just wanted it for the steering column and then found one with an automatic column which was what he really wanted. It's still a complete truck but Texas is a long way from you and the engine is heavy. Used it for work and it is a bear of a truck but when gas got to $4 a gallon it was parked. They LOVE gas.

Bartamos, I can hang loose for a few weeks... I'm not in a hurry at all. Yes the 424.00 is to remove the 305 and break it down to the point of the problem. I'm not even sure where the jam up is... The engine has plenty of oil and plenty of coolnt its just stuck to the point I can't budge it with a breaker bar on the lower pulley.

Here is an old post I just found on here.
https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=592336&page=all

And a Chevy swap link.
http://67-72chevytrucks.com/vboard/showthread.php?t=369663

I would not tear it down until I had a line on parts. The engines were very tough, but never found much favor with truck buyers. Since they were so tough, dealers didn't stock many parts for them. For this reason, not near as many parts for the V6 appear on eBay as other engines. There are usually some valves on eBay, but pistons are a rarity. Try soaking the engine for a week or so with something like Marvel Mystery Oil. I have seen a lot of engines free up and then run a long time. What do you mean by numbers matching? Unless you have the original line set, there is not going to be any documentation of the engine serial number. If you do have the line set, the vehicle is still not going to be worth a lot because of lack of demand.

It ain't stuck. I'm bettin your money on it. Soak it, search on frozen/locked motor advice. Rock the truck in 4th with 5 guys after spark plugs removed and pistons soaked. (center distributor plug removed).Look into plug holes as best you can with a good light to see rust or? No water in oil, no oil in water, probably OK. You DO need the history of the "lock up". If you already drained oil, was is dark or brown/tan? Just dropping the pan and looking at deposits in pan and looking at crank shaft/rods/bores, etc can be a good idea for confidence. You can also take off valve covers and see that nothing is "tangled" or broken. I see your profile says" restore old Chevy trucks for fun. So am I telling you things you already know? Do you do your own work, other than rebuild?

The history on the lock up is the person driving the truck at 55-60 on the highway lost power and had to pull off the exit. Once she was off the exit she tried to restart and the bendix wouldn't turn the motor over... Click click nothing. When I got it I couldn't get it to turn over with a breaker socket on the main pulley.

No water in the oil... No oil in the water.... Plugs look good... ????

I guess a broken timing chain would kill motor and jam while trying to restart. I've never heard of it doing that, BUT.....
Anyway it is worth something that it is in the known event category rather than sitting for 10 years category. It does sound like a major component failure rather than what I was thinking, I.E. "frozen" from being neglected, moisture turning into bore wall rust, all the rotating surfaces dried out/no oil and causing major friction throughout.(soft lockup) That type can be unlocked most of the time. I am now thinking front end (chain/jammed) or rear end (clutch/tranny locked/jammed/broken).(hard lockup). But again I'm assuming this type owner checked oil and water, etc. and these motors don't break much inside. Super, super, super, strong components. Others may have had this happen and may post.

It could easily be a totally different thing that caused her to quit then and to be stuck now. It could have jumped time or the distributor advanced and got stuck. It is common for engines to get stuck from sitting. I would try something like Marvel Mystery Oil. If you can't turn it with prying on the ring gear, I would suggest pulling a head, getting a 3.98 seal driver and pushing down on a piston with something like an OTC 938 Push/Puller and use head bolts for legs for the push. I do this on stuck 302 engines with 4" bore. The 305 has a 4.25 bore, but I think you wouldn't hurt anything with a 1/4 under bushing driver. Pulling the heads is not a major undertaking, and if you can get her to turn 360, you might not have to do much at all to get her running.

Who knows what happened to it in the first place. I remember going out on a call to a person who had been driving all day with a dead generator. Finally the motor quit and of course the it wouldn't turn over. A boost and new generator brushes got him going. Had he parked her then. The motor would probably be stuck by now

You want the guy to buy a $200 push puller? Remember you are one of the only guys with all that stuff at your disposal. That method has the least amount of leverage of anything mentioned. Don't pull the heads yet. Soak thru plug holes, push by hand in fourth gear. Listen for any bad noise. Check tranny for neutral position and clutch shifting. Start with that type thing first. Crenwelge does know his stuff but has more equipment than Gas Monkey Garage.(which is also in Texas). Whatever you "pull" you better find gaskets first, on that motor. Tell us this is not an automatic. Tell us how long you think it was sitting after the event on the highway. I assume the clutch/tranny is not locked to the motor somehow or you could not have loaded/towed it home without dragging it.
Somebody like HRL would know how to look at the Dizzy rotor and the valves, peek at the pistons and tell if it slipped timing, on a motor you can't rotate, without taking much apart.

I'd buy a gallon of KROIL, ( www.kanolabs.com ) pour about 3-4 ounces into each spark plug hole, and wait about a week, then put a pry bar to the flywheel ring gear teeth under the bellhousing. In the meantime, drop the oil pan and look for discolored/damaged connecting rods. Losing power at highway speed and refusing to turn over sounds suspiciously like a seized-up rod bearing. If so, that 305 is a boat anchor- - - -you really don't want to get into a crankshaft replacement/regrind on one of those engines!

For a daily driver, buy a Peterbilt 3-axle tractor with a Cummins Big Cam 400 in it- - - -you'll get better fuel mileage!
Jerry

When you tried to turn it with a breakover bar were all the spark plugs out? If not try it that way before you get crazy and start pulling the motor apart. If that doesn't allow it to turn over then start with the easy things first. Soaking the cylinders, pulling the timing cover, pull intake and heads. Doing each thing then checking for the problem area. If at that point you don't find/cure the problem visit your local banker and call your machine shop. Be prepared for sticker shock when it's done.

If all else fails, pulling the heads is about the only option. But I would exhaust all other methods first. There is a very good chance that soaking it for a week or so would dissolve the rust or carbon build up.

If this doesn't work, I have freed quite a few engines by pushing down on a piston. I use heavy pullers that I use in my business, but a lot of parts houses will loan or rent pullers for one time use. With 17 tons, something is going to give. I have never had a piston to go to pieces, but if it does, you had nothing to lose anyway. If you can't get away with honing the bores and a set of rings, I would find a different engine. If you are gonna pull the engine, I would have a running engine on hand to replace it. They were expensive to rebuild in their day, and they have become very expensive to rebuild now. And after you're done, you would have an engine that would be almost impossible to sell.

The good news is that if it is seized badly, and you want to replace it, they are almost impossible to sell and therefore are very cheap to buy. Try for a few months to find a runner near you. The easiest thing to do, and least expensive, is put another in there. There is a small market for some of the parts off of the old one. Don't throw it away. If you are dreaming of a hot rod-ish type motor, go Chevy motor.

Here is another option to ponder if seized badly:
If you are not in love with this truck and did not pay a lot for it. Sell it as is. Plenty of Chevys out there.
There is plenty of hope left for getting it unseized. But you have to follow the suggestions re: Soaking and turning motor. Some people use Diesel oil? I think.