305v6 = very slow pig - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Suicide-D · 08-02-2002, 08:12 PM

I got the brakes bled on the 68 today and finally drove it around. Maybe it is because the vehicle I'm comparing it to is way out of it's league (my 71) but that thing is incredibly slow through first gear...I floored it and barely moves. once it gets up to speed it felt ok but manit tokk forever to get there. The thing only has a 1 barrel carb on it. anyone else familiar with these v6's? I just can't beleive it is suppose to be this slow. I know I need to tune it up and adjust the carb but jeez. I actually was regretting my purchase.

Super Chevy · 08-02-2002, 08:58 PM

might want to throw a 2bbl on it, sounds like that 1bbl is choking it (1bbl is what 195cfm?) ...

Suicide-D · 08-02-2002, 09:10 PM

I'll have to look into that. Anyone know if I can use the same intake? I know I won't be able to find a performer for that! The base does look similar to a two barrel

**ThreeQuarter** · 08-02-2002, 11:41 PM

I dunno...I kinda think it might be a lost cause trying to get these things to go fast. They're made for torque...I mean TORQUE! so they're naturally gonna be less than peppy. They're so massive and I think they have a really long stroke. Bet you could put a house behind it and it wouldn't be any slower, though.

Talk to me if you get really disappointed in your purchase.

Suicide-D · 08-02-2002, 11:50 PM

I know it is all just a comparison thing... I got the new to me burb out of the shop and thought it was slow for a 350...uummm it's a 5000 lb vehicle it may not snap your head back... I've been ruined by my 71... I'm going to change the cap, rotor, plugs, points and condenser and the oil and see what that does... I know the carb is running rich and needs some attention also. I know that no power steering is going to kill me... I had forgotten how much muscle it took.... and you'll be the first one I pm if I lose faith

**ThreeQuarter** · 08-02-2002, 11:53 PM

Dangit, I thought you would say that. I need another truck like I need a hole in my head...but, yes please contact me! LOL!

Good luck with the tuneup!

Erl · 08-03-2002, 12:33 PM

I have a 305EV6 with a 2-barrel carb and it runs pretty well. Although your idea of slow and mine could be different. If you are ever up in Dallas I will let you take it for a spin. I also have a 2-barrel manafold and carb off of a 305 "D" (1963-64) that is in fair shape.

TERRYP · 08-04-2002, 02:05 AM

The faster you get it to run, the more fuel it will consume. I believe that this is the all time GM champion inefficient engine. The really bad thing is that you cannot blow it up or ovrheat it, therefore giving you an excuse to change engines. I finally ran mine in a destruction derby, only way I could kill it. Of course I won. Thankfully some kid bought it at the end of the derby. He's probably still trying to get it to quit!

**Desert Rat** · 08-04-2002, 09:16 AM

Would i run a 305-6 NO way!!!! but i would if it was used to pull stumps out of the ground,also they used same shroud as a big block on most of them.

**68SWB4x4** · 08-04-2002, 03:27 PM

maybe plumb a nice 200 shot of NOS into one? that would be fun to see how it holds up

Longhorn Man · 08-04-2002, 03:38 PM

I bet it'd live through that too!

Suicide-D · 08-04-2002, 07:53 PM

I changed the wires, plugs, cap, rotor, points and condenser... I adjusted the carb a little...turned both screws in all the way and then back out 1 turn. it runs ok... it's no speed demon but it is definately better than before. I also dumped a bottle of real lead in it and about 15 gallons of Super. Anybody have any thoughts about the valve seats? I bet money they aren't hardened... can I hurt it any by running a lead additive if they have been changed?

08-02-2002, 08:12 PM	#1
Suicide-D Registered User Join Date: Jan 2001 Location: Katy, TX...but the love of my life resides in Dublin,OH. Posts: 1,408	305v6 = very slow pig I got the brakes bled on the 68 today and finally drove it around. Maybe it is because the vehicle I'm comparing it to is way out of it's league (my 71) but that thing is incredibly slow through first gear...I floored it and barely moves. once it gets up to speed it felt ok but manit tokk forever to get there. The thing only has a 1 barrel carb on it. anyone else familiar with these v6's? I just can't beleive it is suppose to be this slow. I know I need to tune it up and adjust the carb but jeez. I actually was regretting my purchase.

08-02-2002, 09:10 PM	#3
Suicide-D Registered User Join Date: Jan 2001 Location: Katy, TX...but the love of my life resides in Dublin,OH. Posts: 1,408	i'm not sure I'll have to look into that. Anyone know if I can use the same intake? I know I won't be able to find a performer for that! The base does look similar to a two barrel

08-02-2002, 11:41 PM	#4
ThreeQuarter Senior Member Join Date: Jun 2000 Location: Texan in Iowa Posts: 2,522	I dunno...I kinda think it might be a lost cause trying to get these things to go fast. They're made for torque...I mean TORQUE! so they're naturally gonna be less than peppy. They're so massive and I think they have a really long stroke. Bet you could put a house behind it and it wouldn't be any slower, though. Talk to me if you get really disappointed in your purchase. __________________ Ben '68 Chevy C10 Custom LWB 327/TH400 2nd owner '16 GMC Sierra 1500 SLE Dblcab 4wd 5.3

08-02-2002, 11:50 PM	#5
Suicide-D Registered User Join Date: Jan 2001 Location: Katy, TX...but the love of my life resides in Dublin,OH. Posts: 1,408	gmcblu I know it is all just a comparison thing... I got the new to me burb out of the shop and thought it was slow for a 350...uummm it's a 5000 lb vehicle it may not snap your head back... I've been ruined by my 71... I'm going to change the cap, rotor, plugs, points and condenser and the oil and see what that does... I know the carb is running rich and needs some attention also. I know that no power steering is going to kill me... I had forgotten how much muscle it took.... and you'll be the first one I pm if I lose faith

08-02-2002, 11:53 PM	#6
ThreeQuarter Senior Member Join Date: Jun 2000 Location: Texan in Iowa Posts: 2,522	Dangit, I thought you would say that. I need another truck like I need a hole in my head...but, yes please contact me! LOL! Good luck with the tuneup! __________________ Ben '68 Chevy C10 Custom LWB 327/TH400 2nd owner '16 GMC Sierra 1500 SLE Dblcab 4wd 5.3

08-02-2002, 08:58 PM	#2
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	might want to throw a 2bbl on it, sounds like that 1bbl is choking it (1bbl is what 195cfm?) ...

08-03-2002, 12:33 PM	#7
Erl Registered User Join Date: Mar 2002 Location: Dallas, TX Posts: 555	I have a 305EV6 with a 2-barrel carb and it runs pretty well. Although your idea of slow and mine could be different. If you are ever up in Dallas I will let you take it for a spin. I also have a 2-barrel manafold and carb off of a 305 "D" (1963-64) that is in fair shape. __________________ 1968 GMC 305 V6 3/4 4x4 Stepside 06 Corvette Daily Driver Dallas TX

08-04-2002, 02:05 AM	#8
TERRYP GYRO GEARLOOSE Join Date: Jun 2000 Location: Nevada City, CAEverett, WA Posts: 361	The faster you get it to run, the more fuel it will consume. I believe that this is the all time GM champion inefficient engine. The really bad thing is that you cannot blow it up or ovrheat it, therefore giving you an excuse to change engines. I finally ran mine in a destruction derby, only way I could kill it. Of course I won. Thankfully some kid bought it at the end of the derby. He's probably still trying to get it to quit! __________________ Nevada City, CA Everett, Washington 57 3/4 rat, 235, 3spd 66 C-10 Panel, SWB. 350 from '68, 200R4 tranny, 3.07 rear ratio, restoring 68 C10 LWB 350 4spd, 4.56 rear dump runner 82 Camaro, 305, THM-200-R4 84 Monte Carlo 305 TH350, land tuna 85 Tercel SW, snow runner DISGRACED OUTLAW MEMBER OF THE DRUM BRAKE CLUB

08-04-2002, 09:16 AM	#9
Desert Rat Senior Member Join Date: Dec 1999 Location: Darrington, Washington Posts: 3,963	Would i run a 305-6 NO way!!!! but i would if it was used to pull stumps out of the ground,also they used same shroud as a big block on most of them.

08-04-2002, 03:27 PM	#10
68SWB4x4 Strongman Garage Join Date: Apr 2000 Location: Salinas, CA Posts: 10,241	maybe plumb a nice 200 shot of NOS into one? that would be fun to see how it holds up __________________ Kalle 68 GMC Suburban 1500 4x4 SOLD 69 Pontiac Lemans 99 Silverado 4.8 5 speed ECSB [ Facebook Instagram Subscribe on YOUTUBE

08-04-2002, 03:38 PM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	I bet it'd live through that too!

08-04-2002, 07:53 PM	#12
Suicide-D Registered User Join Date: Jan 2001 Location: Katy, TX...but the love of my life resides in Dublin,OH. Posts: 1,408	well it's not so bad after all.... I changed the wires, plugs, cap, rotor, points and condenser... I adjusted the carb a little...turned both screws in all the way and then back out 1 turn. it runs ok... it's no speed demon but it is definately better than before. I also dumped a bottle of real lead in it and about 15 gallons of Super. Anybody have any thoughts about the valve seats? I bet money they aren't hardened... can I hurt it any by running a lead additive if they have been changed?



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