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Is the 305 Motor decent?

E

Eric W

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The truck I'm looking at has the 305 motor in it. Its an 86, so it should have the 2 barrel carberuator in it. Naturally, not my first choice but at the price I'm looking at and the low miles of the truck its hard to resist. I really wanted a 350 EFI model but I after thinking about it, the carb'd model might be easier to rip out of the truck to do a motor swap later on with less wires and slightly less displacement.

I read a review in 4 wheeler magazine back in 86 and the 305 auto Jimmy ran a 19.x in the 1/4. That is slug slow haha. I'm wondering if that 305 is going to have the nuggest available to drive larger tires which will slow it down even more.

Bottom line- does this motor suck or what?
 
The motor isn't inherently bad in regards to reliability...it's no more or less reliable than a 350 of the same era.

However, it just can't make the power of the 350. It's also more prone to detonation because the compression is 9.2:1 on the 305's, and that's borderline on 87 octane with that engine design. (heads, etc)

Not a very good candidate for bigger tires, etc., especially if you don't plan on regearing the axles.

Even with 235x75R15's, the 305/3.08/700R4 combo was not anywhere near "peppy", although you could hold it in 2nd a long time. :)
 
i would hold off. mine had 305 in it, and i didnt like the power. i swapped in a 350 pretty quick.

check www.autoshopperonline.com frequently. i always see blazers in there at decent prices. i just got one for my buddy. 1991 gmc 5.7 ltr for 2900.00

a 305 is a boat anchor. and i think ill get backe don that.

good luck
 
Eric W said:
Its an 86, so it should have the 2 barrel carberuator in it.

Bottom line- does this motor suck or what?
Click to expand...

Nothing in 1986 that was installed in trucks had a 2 barrel carburator. Even the 4.3 V6 had a 4 barrel Q-jet in 1985 and 86.

Bottom line, yes, that motor sucks.
 
my old 86 k10 had a 305 in it. i put an edelbrock performer intake, and headers on it. then i swapped in 3/4 ton gear with 4.10,s, i could spin my 38's all day long. the motor only had 3,000 miles on it when i got it
 
Just a thought. If you are getting a really good deal on the truck would you have enough left over to go ahead and do the swap right away. If it's a really solid truck that may be something to consider.
 
Darn the Vin decoder I ran musta been wrong. Anyway thats what I figured about that motor. The truck though, heres the positive details:

It has 34K original miles (a trusted friends' dad who I've known for years)
It passed MD state inspection 2 years ago, so it should need little/no work to pass again
Owner replaced many suspension parts tie rod ends, bearings etc that had worn out from sitting
It passed emissions with flying colors last time around
The interior is really clean
The body is in great shape, some rust spots but not a total rust bucket
Silverado package
It is stock, never been off-roaded or modded. Never wrecked.

$1000.

This is not going to be a DD and I intend for it to be a project vehicle. So an engine swap is definately on the to-do list.

I have physically seen the vehicle, although not driven it yet (opposed so some truck I get off ebay that I have no clue what has happened to it.

At that price, being low miles and from a trusted owner with knowledge of its history, thats why I was considering that truck so heavily. :D
 
If the truck is clean , and has what you want , buy it . You can replace the motor later .

Mine has a 305 still in it . I take care of it , and its been rock solid reliable .

No powerhouse , but it works well in my case . I wheeled and drove daily on 33's with highway gears . Won't win any races , but trucks shouldn't be hot rodded anyway .

I have 33's still , I did a cheap 3.73 swap ( almost free ) . And its fine for now until , I can afford better .

Its all money , if you have it , buy a better motor :k5: :k5:
 
If this helps at all... I just bought my '85 K5 a few months back with a 305 in it. I paid $3000 for it and I'm about to invest atleast that much in a 383 to put in it. If I'm willing to pay more for a new motor than I did the truck, you can probably guess that the 305 leaves much to be desired.
 
Better yet, if it runs good, leave well enough alone, and save money for anything else you want, like a larger motor when the current one goes, better gearing, whatever.

Buying a perfectly running vehicle to rip out the engine is like paying top dollar for a garage kept, straight sheet metal truck you know is going to get hammered on the trail. My buddy spent $5000 on a VERY nice K5 and then proceeded to remove any resale value that truck had in one wheeling trip. Why pay for a running, driving truck when you could just as easily get a non-runner that needs a motor?

If you know you want a strong motor, wait until you find a 350, (or larger) plain and simple, or until you find a truck with no/blown motor, at an EXCELLENT price, and put a new engine in it.

350 K5's just aren't that hard to find, shouldn't settle for a 305 if thats not what you want.

Edit: But $1000 is a good price if everything is in good shape, even if it does have the 305. :)
 
$1000?!?!?!? Jump all over that. Especially with low mileage and in that good of shape. I'm willing to bet you won't find a better deal. Maybe my 305 is just tired because of the 178,000 miles. and I paid $3000.
 
So would I!!

I wish I could find a decent K5 for 1000 bucks that wasnt rotted out or the motor wasnt junk!....I think the 305 is a good motor,not chevy's best by any means,but its still a small block,the 86 305 I put in my 79 C10 really goes right along,much better than a 250 six!....As long as you dont go too far overboard with big tires and high gears,I think a 305 would be enough to get you by for quite a while--and dont forget the smaller motors get better gas mileage too,at todays prices for gas,that should be a consideration too...power isnt everything,its fun to have a big block and lots of power,but the more power you have,the easier you can trash axles,tranny's,etc....:crazy:
 
Thats not a bad deal for $1k if the body is solid. I prefer 350's, but I did run a 305 for a while in my 82 and I had a hard time killing it! Filled it up a few times with water and after maintaining it properly, it never missed a beat!! Ran it pretty hard too! And it leaked like the nose on a 3 year old with a cold... But it kep on running til I pulled it for a 350...

One thing about the 2 barrel that makes me wonder. Weren't some late 86's TBI? It's an odd possibility..??.. That would only have 2 barrels.

Even if for some reaosn it is a 2barrel carb'd truck, as long as the body is in good shape.. Sounds like a good deal.
 
A 305 is no torque monster, but if the deal on the is good enough, I say go for it. You can alway swap in a 350 or 383 stroker at a later date. It's all if you think it's worth it to you.
 
Eric all I'm saying is, if nothing else buy the truck, bring it to west Texas and sell it for 4-6 times what you paid for it. If that's not reason enough, I don't know what is. And if you don't have the $1000 to spend, I'm almost willing to send it to you so you don't miss out on such a good deal.
 
If it's the condition you described, for $1000, I would buy it and put a $2500 "For Sale" sign on it the same day! If it sells, great ... go find yourself a 350 K5 for $2500. If it doesn't, you got a heck of a deal on a 305 K5!

Thomas.
 
305s suck ass i swaped it for a 350 but kept the heads<need some new ones


the 305s have a bad way in chewing up camshafts and theyre not the best thing gm put out
 
I'll try to get some daytime pictures of the truck. The owner tells me theres a slight shimmy when he drives it but it goes away when he sprays lube on the universal joint so one might be going. What else should I look for when I'm driving it/looking at it in depth? What are the common, "leak" areas or "problem" areas?

Since I know nothing about wheeling or trucks, it might be a goodthing to start with a 305. I know it might be slow as balls but it sorta like the progression with motorcycles. Start small, work my way up larger. The less power available, the less stuff is likely to break. I'll definatley wheel it stock at first just to see what it can and cannot do, then let the mods begin.

I am mechanically inclined though and I love projects. My last major project was to remove the driveline of my corvette, change the clutch and flywheel, and open the transmission and replace the 3rd gear synchro all on jackstands. And yes my first project for the k5 will be the steering frame brace! :xmas:

As soon as I save up enough $ so I dont have to put myself into debt I'll buy the thing. The truck shouldnt go anywhere anytime soon. But I plan to do it before spring when weekend trips to Rausch Creek and Paragon (for you mid-atlantic people) will happen all the time, or driving around town with the top and doors removed:D.

Im planning on returning to college in the fall, and I work full time now so by then I may not have time to play with the toys. At the very least I should be able to wheel it stock, not cause too much damage, and at the very least sell it for at least what I paid for it. Thanks guys this place has been great, I'm sure I'll be spending much more time here. :saweet:
 
American84K5 said:
the 305s have a bad way in chewing up camshafts and theyre not the best thing gm put out
Click to expand...

In 1980 or so, GM had issues with 305s and flat cams.

There is nothing about the 305 that makes them flatten a cam...GM just got a batch of soft ones around 1980.
 
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