305 Is a Turd Correct?

[Supercharged111]

Not so much. The smaller bore engines were easier to clean up the emissions on with the technology of the time.

You sure it was the bore? There was some sort of mpg driven 5.0 liter limit imposed at some point in the malaise era. Not sure if there was a smog/guzzler tax beyond that or what.

 

[Road Trip]

Not so much. The smaller bore engines were easier to clean up the emissions on with the technology of the time.

Back in the day I used to read articles where because of the difficulty in getting a stick-equipped vehicle past emissions
(compounded by the low percentage of overall sales) there was a time where supposedly no stickshift vehicles would be
offered at all. We tend to forget that back then it was a struggle for them to meet the constantly tightening emissions
regulations with the technology they had plus learning as they went against tight deadlines.

You sure it was the bore? There was some sort of mpg driven 5.0 liter limit imposed at some point in the malaise era. Not sure if there was a smog/guzzler tax beyond that or what.

I seem to remember that once upon a time that on a per vehicle basis EPA testing was that a 15 mpg rating = gas guzzler tax?
But 16 mpg = good to go? But after going over a certain GVWR (> 6000 lbs?) this no longer pertained?
NOTE: I think the current go/no-go gas guzzler tax currently starts at 22.5 mpg and progressively gets much larger?

EDIT: And I seem to remember that back then GM didn't want sell any vehicle that would run afoul of the gas
guzzler tax, partly due to the financial penalty, and also didn't want to draw negative press to themselves for
demonstrable indifference to mother earth. The last time I bought a new vehicle (admittedly a long time ago) I think
the gas guzzler tax was something on the order of $750. But that was long ago, see attached for a
more recent table. (Taken from the following article.)

It's been a long time, so the details are a bit fuzzy now. :0) But I do remember that the goals
of both meeting stricter emissions + also meeting CAFE standards = burning the midnight oil for the
powertrain engineers paid to worry about these things. And some (desirable to me) combos were no
longer offered for sale for running afoul of one or both of these mandated standards?)

 

[Komet]

In the late 70's, GM wasn't sure any V8 was going to be able to hit the EPA's targets for the mid 80's, but if there was a chance, it was with the 305. Fortunately fuel injection technology (and smog pumps, etc) worked so well that it put the 350 back on the table.

 

[mwb6700]

Our family ran a 84 Caprice and a 86 GMC over 300k miles each on the stock 305s over 15 year timeframe. Typical valve guide leakdown main issue. Kept good oil in them. The Chevy got an Edelbrock non-egr Manifold early on. Ran Bosch plugs and kept the Quadrajets tuned up. And had an excellent mechanic who pointed out that despite oil leak down at least you knew the topend was getting lubricated

 

[Vic327]

I don't think the emissions was a big part of not putting a 5 speed with the 350. A slow shift does puff some fuel but 305/350 isn't a big difference. Have a look at the torque rating on the NV3500 and the 350 plus GM charged a grand more for the auto.

 

[barry_g]

Most of the 305 lore is based on myths the only difference is about 1/4 inch bore size and smaller combustion chambers. I've had people swear they had a 350 until I ran the block number and it was a 305.

I am one of those odd ducks.. my first 305 that was interstate worthy was a 1984 monte carlo SS.. right out of a barn, it only needed a clean and wax job. I took it past the 100k miles mark. had low miles. that was 1996. the first thing to ever pass me was a saab900 turbo. LOL. Nice engine, the HO.
I then went through 3 more.. very low hp 1984 grand prix, carbed 3 speed auto.. the glory with that one was reaching 280k miles... on a 3 speed auto. Very smoky in the end. My friend pointed out the front grill open down low,must have kept the oil pan cooler. I was all highway.
various other g body..just daily drivers.
jump ahead to the 96 gmc with 5 speed.. holy cow. 5652 pounds and actually moves. I really did have to get underneath and check side of the block. Not single complaint on power in 393k miles. Even maine coast with a boat, nothing to it.

powernation has a great series where they played with a 305 all the way to stroker... at 505hp.
if gm made it to be small..kinda stuck with it, unless you want to relapse to carbs and cams, heads... get some real electronic timing curve in it too. HP is nothing but a throttle ramp. Trucks are not normally allowed to just slam it open.

 

[jd33173]

So I have a 93 extended cab with a 4l60e and a 305. I know the older 305’s were “smog” engines made for mpg not performance. From what I have researched these tbi 305’s are no different. Just want to make sure there are no 305 masters in here that know secrets before I throw a 350 in it lol

Is it old and slow ( like myself)? Yes. Can it be souped up w enough money? Also Yes. The question is : is the juice worth the squeeze? Will the performace generated for the money spent be worth it given the fairly common availability of other platforms that lend themselves to better performance per dollar? Most sentient beings i have encountered tend to say "no". Having a 305 myself, i agree and have acquired a donor truck w a 350 which i plan on upgrading.

 

[Scooterwrench]

Most of the 305 lore is based on myths the only difference is about 1/4 inch bore size and smaller combustion chambers. I've had people swear they had a 350 until I ran the block number and it was a 305.

I don't think those people ever had a 350. If they had they would have known the difference. 305's work OK until they have to actually do some work. Ever wonder why there are no 305's in 3/4 and 1 ton trucks?

 

[L31MaxExpress]

I don't think those people ever had a 350. If they had they would have known the difference. 305's work OK until they have to actually do some work. Ever wonder why there are no 305's in 3/4 and 1 ton trucks?

Not true at all. GM put 305s in C50 and C60 chassis school buses and they were actually common in C20 suburbans and G20 vans in the 80s.

My 1983 305 had no issue towing a fairly heavy, un-aerodynamic 24 ft pontoon boat. The 305 towed about as well as the 350 TBI that replaced it. The 350 had a little more torque but barely enough to notice.

 

[Scooterwrench]

Not true at all. GM put 305s in C50 and C60 chassis school buses and they were actually common in C20 suburbans and G20 vans in the 80s.

My 1983 305 had no issue towing a fairly heavy, un-aerodynamic 24 ft pontoon boat. The 305 towed about as well as the 350 TBI that replaced it. The 350 had a little more torque but barely enough to notice.

I'll take your word for it,just never seen it myself.