305 Motor Pros and Cons? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

skillet · 11-10-2005, 08:58 PM

Is the 305 a good motor? Like say in a '93 Chevy truck? All I've dealt with is 283 and 350. Thanks for any comments.

krue · 11-10-2005, 09:18 PM

It's a dog, imo.

**N2TRUX** · 11-10-2005, 10:32 PM

There is nothing really "wrong" with a 305. It's just like the old saying that " their is no replacement for displacement" meaning why not go with a 350.

Fatback · 11-10-2005, 11:15 PM

It all depends on what you want to use it for. I owned a 1979 Chevy Truck w/305, for 11 years. I never had any problems at all.....though not a hot rod. The later 305's got a little more power.
I am running a 1996 305 in my 70,I am very happy with it. I dont plan on racing or pulling a travel trailer.It is a good motor for a daily driver, But if you want high performance, it's not the best choice.

phantom dually · 11-10-2005, 11:42 PM

I have a 305 in my 94 c2500. Great motot until you pull something. Pulls fine just not fast ebough for me!! My 94 just turned 68K original miles.

bad68bowtie · 11-11-2005, 12:53 AM

I've got a 305 in my truck and it doesn't make much horsepower and doesn't make up for that in gas mileage either. I would definitely go for a 350 or even somethin like a 327. I guess the 305 gets the job done but it is a dog and I can only imagine what it'd be like if I didn't have headers on it with an Edelbrock carb. and intake.

86swb · 11-11-2005, 09:05 AM

The 350 is a better engine in my openion. The 45 extra cubic inches makes a difference. That 350 is just a all around great little engine. IMO

Woody · 11-11-2005, 09:19 AM

In most cases the 350 will get the same or better gas milage as the 305. I put a '85 305 in my '69 years ago. It was a good motor just didn't have a power. The first 1/2 throttle was peppy, but from there to the floor there was no response. You couldn't even tell when the 4 bbl came in. I called it my nutless engine, because it had no balls.

I got ~13 mpg with it. The 350 that it replaced got 12.5mpg with a good tuneup and had the power to move the truck.

Tx Firefighter · 11-11-2005, 11:09 AM

They usually do suck powerwise in "stock tune".

I've run a few of them that I rebuilt with flat top pistons and a better cam and they wake up decently.

Remember, on most of them, the factory compression was low enough to start with a pull rope and the cam lobes a practically round.

Jason915 · 11-11-2005, 04:15 PM

The earlier ones were DOG's due to low compression and the emissions requirements. They can be made into great running engines though in fact the L-69 ran better than allot of stock late 70's early 80's emissions 350's. My uncle has a 68 C20 with a stock L-69 305 out of an SS Monte and it runs much better than my grandma's 79 C-20 with a 350. You can build a 305 that will have plenty of power for a daily driver and will do better on gas than a 350 if built right. I wouldn’t go out of my way for a 305 but if I had one available to build I wouldn’t hesitate to drop it in a light duty truck or Blazer. The L29 Vortec 305 runs real good and it gets good MPG. A friend of mine just built a 305 for his 86 Blazer and it runs strong and gets 18 MPG on the Highway and this is what it is

305 .030 over w/ flat top pistons
L29 Vortec cylinder heads
Comp Cam CS X4 250H-11
Edelbrock intake
500 CFM Q-Jet
Full Length headers
HEI has been professionally tuned and re curved

With 3.42 gears this Blazer actually moves quite well and tows a 16’ fishing boat with no problems.

A.P. · 11-11-2005, 06:15 PM

I throw my 305 away and installed a 350. Much better engine.

A.P.

Tx Firefighter · 11-11-2005, 07:06 PM

Quote:

Originally Posted by A.P.

I throw my 305 away and installed a 350. Much better engine.

A.P.

I like guys like you. That's how I've gotten several free 305's.

garold99 · 11-11-2005, 07:25 PM

I had a 305 in my 79 Camaro. It was a piece of crap. I think the joggers could outrun me.

Swore I would never own one again. Running a 350 now and love it. I do like the 327's also.

roger0080 · 11-11-2005, 08:11 PM

Fatback sums it up best.

I swapped the 307 out after it died to a used 305 and I liked it. I used it for a daily driver. All depends what you want.

A.P. · 11-12-2005, 06:34 AM

Tx Firefighter if I would of known you wanted another 305 that was no use to me. I've would of send it to you. I tried to give it away to my family or friends near by my house, but no body wanted it after I told them it was a 305. So I was forced to throw it away in the auto junk yard.

73737373 · 11-12-2005, 06:41 AM

Everyone has different tastes and opinions, some purely speculative, others can be backed by fact. We ARE and interesting group.

Longhorn Man · 11-12-2005, 07:34 AM

Tx noted the one good thing about 305 motors... they can be had in any part of the country for free, or not much more. IMO, anyone who pays more than 100 bucks for a non rebuilt 305 long block is getting ripped off. (Talkin older carbed ones here, not the Injected ones)

stepside454 · 11-12-2005, 11:16 AM

from a purely performance standpoint dollar for dollar a 350 is a much better choice obviosly....unless you get a good runnin 305 for free. as far as are they a good motor, sure, they are as reliable as most any other small block.
As someone stated earlier, properly preparred , they can run very strong. I had a 305 I built in my 86 GMC Caballero that ran 13.70s with 3.08 gear, idled nice, 16" of vacuum & great MPG. so I think callin a 305 worthless is a bit dramatic.

ChevLoRay · 11-12-2005, 11:24 AM

Man, I remember when the hottest small-block was a 283, "bored 60". Seems like that was what we called a 301. Then, Chevy came out with the 327, for '62. You could swap the crank into a 283 block and then you had a 301.

The 307 was a smog dog, that may have been issued with good intentions, but never had anything going for it. I scammed onto a 307, and a 60K mile 327 (275 Horse), plus 4 pairs of heads, from my late uncle....all back in '79. I had a '67 Impala that had a worn-out 283 that I intended to replace with the 327, but sold the car and finally gave away all the other stuff. Oh, well.....

I think the 305 is a more usable engine than the old 307, but like has already been said....there's no replacement for displacement. I'd like to have a good 406 to put in my truck, but there's also a 427CID small block out in the market place.......but, no money in the budget at this time for that new engine. When I do, I am thinking that the 383HT crate engine will do the job for me....with a 700R4 behind it.

Long Roof · 11-12-2005, 12:08 PM

My Bro-in-law had a Monte SS with the 305 and it wasn't horrible. I think he got it into the 14.50's. Hell my stock 96 Impala SS barely got into the 15.80's, and before you start screaming about weight they were only 700#'s apart.

305 is an o.k. engine if that's what you have to work with. I wouldn't thow it away.

Aaron

stepside454 · 11-12-2005, 01:29 PM

from a performance stand point I think the ol smogger 307 can be built with possibly better results than the 305 due to the 307s larger bore & short stroke allowing quicker revs & less valve shrouding. either way both can offer decent street performance...neither would be well suited for heavy hauling or towing of course.

HeavyD · 11-12-2005, 04:45 PM

Just for curiosity, if a 305 and 307 were built with decent cam, intake, good carb, and a little head work, which would get better overall mpg?

stepside454 · 11-12-2005, 04:48 PM

assuming you mean under normal driving conditions....not loaded down, Id have to say the 307. under load the 305 might do better than the 307

matthufham · 11-12-2005, 05:40 PM

my mom's 95 1500 with a 305 is pretty darn nice. it's a strong motor, but the 4l60E behind it is terrible. we were sitting at 110,000 miles when we towed for the 1st time. we changed the fluid after we got my truck home, and it's been slipping ever since.

airman1952 · 11-12-2005, 07:13 PM

Hi. First post! Have a 72 k20 with the 402.

Just my opinion, a 305 is just another GM small block. It all depends on how
much goodies you want to put on it to make it run! It's biggest problem is
that "305 cubic inches" just does not sound very sexy! 283 - 302 - 327 - 396- 427 - 454 !!! Now, those sound good!

I have an 84 Z28, with the L69. For an 80's generation car, it does not run half bad!

11-10-2005, 08:58 PM	#1
skillet Registered User Join Date: Sep 2000 Location: denton, tx, usa Posts: 176	305 Motor Pros and Cons? Is the 305 a good motor? Like say in a '93 Chevy truck? All I've dealt with is 283 and 350. Thanks for any comments. __________________ 69 SB GMC LWB Fleetside 350, 09 Pontiac Vibe 2.4 liter

11-10-2005, 09:18 PM	#2
krue Designated A-hole! Join Date: Mar 2003 Location: South Mississippi Posts: 36,450	Re: 305 Motor Pros and Cons? It's a dog, imo. __________________ "If it ain't broke, fix it 'til it is!" Being stupid ain't illegal. We're Still Debt Free Except for the House!!! www.daveramsey.com 70 GMC SWB Stepside project "Green Booger" soon to be 6.0l/4l80e 93 S-10 "Poppaw's Truck"

11-10-2005, 10:32 PM	#3
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,023	Re: 305 Motor Pros and Cons? There is nothing really "wrong" with a 305. It's just like the old saying that " their is no replacement for displacement" meaning why not go with a 350. __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

11-10-2005, 11:15 PM	#4
Fatback Registered User Join Date: Dec 2003 Location: North Central FL Posts: 126	Re: 305 Motor Pros and Cons? It all depends on what you want to use it for. I owned a 1979 Chevy Truck w/305, for 11 years. I never had any problems at all.....though not a hot rod. The later 305's got a little more power. I am running a 1996 305 in my 70,I am very happy with it. I dont plan on racing or pulling a travel trailer.It is a good motor for a daily driver, But if you want high performance, it's not the best choice. __________________ 70 C/10 LWB 69 Cougar 68 Mustang 68 GMC 4X4 SWB

11-10-2005, 11:42 PM	#5
phantom dually Project92 SWB stepside Join Date: Feb 2003 Location: Louisville KY Posts: 4,793	Re: 305 Motor Pros and Cons? I have a 305 in my 94 c2500. Great motot until you pull something. Pulls fine just not fast ebough for me!! My 94 just turned 68K original miles. __________________ 92 C1500 stepside 496 Stroker Competiton Engineering Ladder bars/QA1 coilovers. Dana 60 rear with 4.10 gear and posi. Bonspeed Palisade 20x12 in rear w/335/30/20 and 20x8.5 front w/245/40/20. 5/8 drop with Belltech springs/DJM spindles/drop shocks. WWS Progress thread http://67-72chevytrucks.com/vboard/s...d.php?t=140448

11-11-2005, 12:53 AM	#6
bad68bowtie On the college boy budget... Join Date: Oct 2005 Location: Athens, Georgia Posts: 370	Re: 305 Motor Pros and Cons? I've got a 305 in my truck and it doesn't make much horsepower and doesn't make up for that in gas mileage either. I would definitely go for a 350 or even somethin like a 327. I guess the 305 gets the job done but it is a dog and I can only imagine what it'd be like if I didn't have headers on it with an Edelbrock carb. and intake. __________________ -'68 C10 short/step- 350/350

11-11-2005, 09:05 AM	#7
86swb Born a Chevy Man Join Date: Apr 2005 Location: Navarre, Florida Posts: 10,221	Re: 305 Motor Pros and Cons? The 350 is a better engine in my openion. The 45 extra cubic inches makes a difference. That 350 is just a all around great little engine. IMO __________________ John or 86 (Viet Nam combat Vet-BIG RED ONE) '65-'66 1986 Chevy SWB Silverado 1984 Chevy Longbed Silverado New Kia Sportage (Wife's car and she loves it) CHEVY, American made w/pride! If you can read this, YOU NEED TO THANK A TEACHER! If you can read this in ENGLISH, PLEASE THANK A SOLDIER! GOD BLESS AMERICA AND BLESS OUR FIGHTING TROOPS

11-11-2005, 09:19 AM	#8
Woody Registered User Join Date: Feb 2000 Location: Georgetown, KY, USA Posts: 631	Re: 305 Motor Pros and Cons? In most cases the 350 will get the same or better gas milage as the 305. I put a '85 305 in my '69 years ago. It was a good motor just didn't have a power. The first 1/2 throttle was peppy, but from there to the floor there was no response. You couldn't even tell when the 4 bbl came in. I called it my nutless engine, because it had no balls. I got ~13 mpg with it. The 350 that it replaced got 12.5mpg with a good tuneup and had the power to move the truck.

11-11-2005, 11:09 AM	#9
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: 305 Motor Pros and Cons? They usually do suck powerwise in "stock tune". I've run a few of them that I rebuilt with flat top pistons and a better cam and they wake up decently. Remember, on most of them, the factory compression was low enough to start with a pull rope and the cam lobes a practically round. __________________ I'm on the Instagram- @Gearhead_Kevin

11-11-2005, 04:15 PM	#10
Jason915 Registered User Join Date: Jan 2005 Location: Colorado Springs Posts: 693	Re: 305 Motor Pros and Cons? The earlier ones were DOG's due to low compression and the emissions requirements. They can be made into great running engines though in fact the L-69 ran better than allot of stock late 70's early 80's emissions 350's. My uncle has a 68 C20 with a stock L-69 305 out of an SS Monte and it runs much better than my grandma's 79 C-20 with a 350. You can build a 305 that will have plenty of power for a daily driver and will do better on gas than a 350 if built right. I wouldn’t go out of my way for a 305 but if I had one available to build I wouldn’t hesitate to drop it in a light duty truck or Blazer. The L29 Vortec 305 runs real good and it gets good MPG. A friend of mine just built a 305 for his 86 Blazer and it runs strong and gets 18 MPG on the Highway and this is what it is 305 .030 over w/ flat top pistons L29 Vortec cylinder heads Comp Cam CS X4 250H-11 Edelbrock intake 500 CFM Q-Jet Full Length headers HEI has been professionally tuned and re curved With 3.42 gears this Blazer actually moves quite well and tows a 16’ fishing boat with no problems. __________________ 1971 GMC K1500 SWB Fleetside, 4" skyjacker softride and, 14 Bolt FF, HD Dana 44 4.10's 1970 K5 TBI conversion lifted etc SOLD 1968 C20 camper truck SOLD “To ban guns because criminals use them is to tell the innocent and law-abiding that their rights and liberties depend not on their own conduct, but on the conduct of the guilty and the lawless.” Jeff Snyder

11-11-2005, 06:15 PM	#11
A.P. Black 72 Chevy Join Date: May 2002 Location: Los Angeles, California Posts: 662	Re: 305 Motor Pros and Cons? I throw my 305 away and installed a 350. Much better engine. A.P.

11-11-2005, 07:25 PM	#13
garold99 Registered User Join Date: Nov 2004 Location: Moore, Oklahoma Posts: 129	Re: 305 Motor Pros and Cons? I had a 305 in my 79 Camaro. It was a piece of crap. I think the joggers could outrun me. Swore I would never own one again. Running a 350 now and love it. I do like the 327's also.

11-11-2005, 08:11 PM	#14
roger0080 Registered User Join Date: Nov 2000 Location: Carver County, Minnesota, USA Posts: 626	Re: 305 Motor Pros and Cons? Fatback sums it up best. I swapped the 307 out after it died to a used 305 and I liked it. I used it for a daily driver. All depends what you want. __________________ 72 Chev C-10 90% restored (former AZ truck) ... 71 Chev K-20 Cheyenne my vacation crusier... 72 Chev C-10 Now retired and striped after many faithful miles... 72 GMC 1500 Retired to the junk yard after bought new in '71...

11-12-2005, 06:34 AM	#15
A.P. Black 72 Chevy Join Date: May 2002 Location: Los Angeles, California Posts: 662	Re: 305 Motor Pros and Cons? Tx Firefighter if I would of known you wanted another 305 that was no use to me. I've would of send it to you. I tried to give it away to my family or friends near by my house, but no body wanted it after I told them it was a 305. So I was forced to throw it away in the auto junk yard.

11-12-2005, 06:41 AM	#16
73737373 Registered User Join Date: Sep 2005 Location: Oklahoma USA Posts: 1,000	Re: 305 Motor Pros and Cons? Everyone has different tastes and opinions, some purely speculative, others can be backed by fact. We ARE and interesting group. __________________ 1968 Custom SWB, 327/3 speed OTC 1969 CST LWB, 402/400 1970 CST LWB, 402/400 1970 Sierra Grande LWB, 350/350 1971 Cheyenne LWB, 350/350 1972 Cheyenne Super LWB, 402/400 1972 Sierra Grande LWB, 402/400 1979 Silverado LWB, 350/350 1984 Suburban 1990 454 SS 1991 Silverado, X-cab, 4.3/5 speed Getrag 2005 Silverado Crew Cab Corvettes: 75, 77, 78, 93, 96



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11-12-2005, 07:34 AM	#17
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 305 Motor Pros and Cons? Tx noted the one good thing about 305 motors... they can be had in any part of the country for free, or not much more. IMO, anyone who pays more than 100 bucks for a non rebuilt 305 long block is getting ripped off. (Talkin older carbed ones here, not the Injected ones)

11-12-2005, 11:16 AM	#18
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	Re: 305 Motor Pros and Cons? from a purely performance standpoint dollar for dollar a 350 is a much better choice obviosly....unless you get a good runnin 305 for free. as far as are they a good motor, sure, they are as reliable as most any other small block. As someone stated earlier, properly preparred , they can run very strong. I had a 305 I built in my 86 GMC Caballero that ran 13.70s with 3.08 gear, idled nice, 16" of vacuum & great MPG. so I think callin a 305 worthless is a bit dramatic. __________________ 75 GMC C-15 short/step factory 454, lowered

11-12-2005, 11:24 AM	#19
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: 305 Motor Pros and Cons? Man, I remember when the hottest small-block was a 283, "bored 60". Seems like that was what we called a 301. Then, Chevy came out with the 327, for '62. You could swap the crank into a 283 block and then you had a 301. The 307 was a smog dog, that may have been issued with good intentions, but never had anything going for it. I scammed onto a 307, and a 60K mile 327 (275 Horse), plus 4 pairs of heads, from my late uncle....all back in '79. I had a '67 Impala that had a worn-out 283 that I intended to replace with the 327, but sold the car and finally gave away all the other stuff. Oh, well..... I think the 305 is a more usable engine than the old 307, but like has already been said....there's no replacement for displacement. I'd like to have a good 406 to put in my truck, but there's also a 427CID small block out in the market place.......but, no money in the budget at this time for that new engine. When I do, I am thinking that the 383HT crate engine will do the job for me....with a 700R4 behind it. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

11-12-2005, 12:08 PM	#20
Long Roof Old School, New Style Join Date: Jun 2005 Location: Monroeville, Ohio Posts: 790	Re: 305 Motor Pros and Cons? My Bro-in-law had a Monte SS with the 305 and it wasn't horrible. I think he got it into the 14.50's. Hell my stock 96 Impala SS barely got into the 15.80's, and before you start screaming about weight they were only 700#'s apart. 305 is an o.k. engine if that's what you have to work with. I wouldn't thow it away. Aaron __________________ The Good: - 72 GMC Jimmy 4x4 - 307 cid / 350 th - 70 Chevy Suburban 1/2T 2wd - 454 cid /400 th - 96 Chevy Impala SS - mainly stock - 98 Chevy Tahoe LT 4x4 - all stock The Bad: - 86 Chevy Suburban 1/2T 4x4 - winter beater The Ugly: - 72 Chevy Suburban 1/2T 2wd - parts truck

11-12-2005, 01:29 PM	#21
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	Re: 305 Motor Pros and Cons? from a performance stand point I think the ol smogger 307 can be built with possibly better results than the 305 due to the 307s larger bore & short stroke allowing quicker revs & less valve shrouding. either way both can offer decent street performance...neither would be well suited for heavy hauling or towing of course. __________________ 75 GMC C-15 short/step factory 454, lowered

11-12-2005, 04:45 PM	#22
HeavyD Senior Member Join Date: Sep 2004 Location: Wakaw, Sask, Canada Posts: 3,180	Re: 305 Motor Pros and Cons? Just for curiosity, if a 305 and 307 were built with decent cam, intake, good carb, and a little head work, which would get better overall mpg? __________________ "You can take the man out of PA, but you can't take PA out of the man"

11-12-2005, 04:48 PM	#23
stepside454 Registered User Join Date: Nov 2003 Location: st. louis area Posts: 1,551	Re: 305 Motor Pros and Cons? assuming you mean under normal driving conditions....not loaded down, Id have to say the 307. under load the 305 might do better than the 307 __________________ 75 GMC C-15 short/step factory 454, lowered

11-12-2005, 05:40 PM	#24
matthufham Registered User Join Date: Feb 2005 Location: Carl Junction, Missouri Posts: 2,061	Re: 305 Motor Pros and Cons? my mom's 95 1500 with a 305 is pretty darn nice. it's a strong motor, but the 4l60E behind it is terrible. we were sitting at 110,000 miles when we towed for the 1st time. we changed the fluid after we got my truck home, and it's been slipping ever since.

11-12-2005, 07:13 PM	#25
airman1952 Registered User Join Date: Nov 2005 Location: Oregon Posts: 3	Re: 305 Motor Pros and Cons? Hi. First post! Have a 72 k20 with the 402. Just my opinion, a 305 is just another GM small block. It all depends on how much goodies you want to put on it to make it run! It's biggest problem is that "305 cubic inches" just does not sound very sexy! 283 - 302 - 327 - 396- 427 - 454 !!! Now, those sound good! I have an 84 Z28, with the L69. For an 80's generation car, it does not run half bad!

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