307 motor ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

outlawchevy · 05-08-2006, 09:55 PM

what kind of horse power does a 307 have and what is it capable of thanks for any info .

taylorde · 05-08-2006, 10:40 PM

There was an article last year I believe that had tech on that motor. I believe they only got it up to about approx. 350 or so maybe alittle more not sure. Check classic trucksmag and custom classic trucks mag.

Green Machine · 05-08-2006, 11:37 PM

Depends what you have and want to do, if you want to built something fast, pass. If you just want to drive it with some decent power and mpg, they are OK. I rebuilt mine because it was original to the truck. Stock rebuild with a little cam and 4bbl, it will get your attention.

72armyswbtruck · 05-09-2006, 12:20 AM

307 I have never heard of one, someone got the specs or history of it for me?

jimfulco · 05-09-2006, 02:01 AM

Chevy used a 307cid small-block from '68 to '73 or so. It had a 3-7/8" bore (like a 283), and a 3-1/4" stroke (like a 327). No relation to the Olds 307 used by GM later on.

Nitroblood · 05-09-2006, 02:32 AM

I have a '71 307 block that I plan on punching out .125 over, which will make it a 327. The 307 was actually a 283 with 327 internals, with tiny valves and small chambered heads. They make good torque, just not very great top end.

At first I was a little cold about finding out I had a 307, until my co-worker told me to keep it and make a 327. So, hey what the hell, I'm going to work with what I got and hopefully enjoy the results.

72armyswbtruck · 05-09-2006, 03:09 AM

Sweet, I have gained new knowledge
Thanks

RicksTrucks · 05-09-2006, 11:17 AM

My 69 SWB came with a 307 from the factory. Had to replace it a couple years ago, due to cracked head, with a crate 350. But will probably put it back in later to keep the truck original.

Anyone know what would be the best enhancement to it for gas mileage?

farside847 · 05-09-2006, 11:22 AM

Quote:

Originally Posted by RicksTrucks

My 69 SWB came with a 307 from the factory. Had to replace it a couple years ago, due to cracked head, with a crate 350. But will probably put it back in later to keep the truck original.

Anyone know what would be the best enhancement to it for gas mileage?

I have been tinkering with my 307 to improve MPG. Got it up to 14mpg and I dont think I can do any better without a new tranny. (I have a 3sp). Best thing I did was tune it up (1mpg gain) and replace the fan with electric (1mpg gain)

sneakysnake · 05-09-2006, 11:38 AM

My experience with the 307, I had a 283 that pitted the block between the #3 and #5 cylinders.So I found a used block to put all my parts in but my 283 was .30 over.I take it to be bored and checked.Well everything was fine until I went to put in the crank.I wound up having to buy all new parts because other that the bore size nothing I had would swap so a $200.00 fix turned into a $1000.00. but it would boil the tires

JRB · 05-09-2006, 12:09 PM

If you get an 1/8th of an inch bored off the cylinder walls it would be like having a small jornal 327. The standard bore on a 307 is 3 and 7/8's and a 3and a 1/4 inch stroke. The 327 is 4inch bore and 3 and a 1/4 inch stoke. I had a 307 resurected into a 327 in my 57 Chevy Bigwindow Short Step. I had a 600 CFM edlebrock and a performer intake. I had the normal mid 80's 76cc heads on it and it ran great with great gas milage. Over 20MPG. Good luck with yours.
JRB

farside847 · 05-09-2006, 01:02 PM

Quote:

Originally Posted by JRB

If you get an 1/8th of an inch bored off the cylinder walls it would be like having a small jornal 327. The standard bore on a 307 is 3 and 7/8's and a 3and a 1/4 inch stroke. The 327 is 4inch bore and 3 and a 1/4 inch stoke. I had a 307 resurected into a 327 in my 57 Chevy Bigwindow Short Step. I had a 600 CFM edlebrock and a performer intake. I had the normal mid 80's 76cc heads on it and it ran great with great gas milage. Over 20MPG. Good luck with yours.
JRB

Wow! what tranny and rear did it have?

05-08-2006, 09:55 PM	#1
outlawchevy Registered User Join Date: Jan 2004 Location: Walker,louisiana Posts: 179	307 motor ? what kind of horse power does a 307 have and what is it capable of thanks for any info . __________________ (If all else fails get a bigger hammer)

05-08-2006, 10:40 PM	#2
taylorde Just A Tool Hand Join Date: Jan 2006 Location: Lovington,New Mexico Posts: 70	Re: 307 motor ? There was an article last year I believe that had tech on that motor. I believe they only got it up to about approx. 350 or so maybe alittle more not sure. Check classic trucksmag and custom classic trucks mag. __________________ :hit:

05-09-2006, 12:20 AM	#4
72armyswbtruck Registered User Join Date: Feb 2004 Location: Idaho Posts: 4,033	Re: 307 motor ? 307 I have never heard of one, someone got the specs or history of it for me? __________________ "Remember, They can Kill You, but they can't eat You, That's against the law!!!!!!!!!"

05-09-2006, 02:32 AM	#6
Nitroblood Registered User Join Date: Sep 2005 Location: Montclair, California Posts: 163	Re: 307 motor ? I have a '71 307 block that I plan on punching out .125 over, which will make it a 327. The 307 was actually a 283 with 327 internals, with tiny valves and small chambered heads. They make good torque, just not very great top end. At first I was a little cold about finding out I had a 307, until my co-worker told me to keep it and make a 327. So, hey what the hell, I'm going to work with what I got and hopefully enjoy the results. __________________ 1972 C / 20

05-09-2006, 03:09 AM	#7
72armyswbtruck Registered User Join Date: Feb 2004 Location: Idaho Posts: 4,033	Re: 307 motor ? Sweet, I have gained new knowledge Thanks __________________ "Remember, They can Kill You, but they can't eat You, That's against the law!!!!!!!!!"

05-08-2006, 11:37 PM	#3
Green Machine Senior Member Join Date: Jul 2004 Location: Estherville, Iowa Posts: 3,371	Re: 307 motor ? Depends what you have and want to do, if you want to built something fast, pass. If you just want to drive it with some decent power and mpg, they are OK. I rebuilt mine because it was original to the truck. Stock rebuild with a little cam and 4bbl, it will get your attention. __________________ 1968 C10 307 3spd Long Fleet ------ http://67-72chevytrucks.com/vboard/s...d.php?t=201103 1970 C10 305 Super T10 Long Fleet --- http://67-72chevytrucks.com/vboard/s...d.php?t=202285 1971 C20 383 TH350 Dana Posi ----- http://67-72chevytrucks.com/vboard/s...d.php?t=206894 2001 GMC Sierra 1500 C3 6.0 Last edited by Green Machine; 05-08-2006 at 11:42 PM.

05-09-2006, 02:01 AM	#5
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Re: 307 motor ? Chevy used a 307cid small-block from '68 to '73 or so. It had a 3-7/8" bore (like a 283), and a 3-1/4" stroke (like a 327). No relation to the Olds 307 used by GM later on.

05-09-2006, 11:17 AM	#8
RicksTrucks Senior Member Join Date: Jan 2005 Location: Claremore, OK 74017 Posts: 2,639	Re: 307 motor ? My 69 SWB came with a 307 from the factory. Had to replace it a couple years ago, due to cracked head, with a crate 350. But will probably put it back in later to keep the truck original. Anyone know what would be the best enhancement to it for gas mileage? __________________ 68 Short Stepside C-10 69 SWB C-10 70 Flatbed C-20 70 LWB C-20 BB402 70 LWB C-10 CST 70 LWB C-10 CST 71 Short Stepside Cheyenne C-10 72 LWB C-10 72 Blazer 4x4 4spd 95 Jeep Cherokee 4x4

05-09-2006, 11:38 AM	#10
sneakysnake It's a catastrophic success. Join Date: Jan 2003 Location: Oklahoma Posts: 2,077	Re: 307 motor ? My experience with the 307, I had a 283 that pitted the block between the #3 and #5 cylinders.So I found a used block to put all my parts in but my 283 was .30 over.I take it to be bored and checked.Well everything was fine until I went to put in the crank.I wound up having to buy all new parts because other that the bore size nothing I had would swap so a $200.00 fix turned into a $1000.00. but it would boil the tires

05-09-2006, 12:09 PM	#11
JRB Senior Member Join Date: Nov 2005 Location: Portland Oregon Posts: 287	Re: 307 motor ? If you get an 1/8th of an inch bored off the cylinder walls it would be like having a small jornal 327. The standard bore on a 307 is 3 and 7/8's and a 3and a 1/4 inch stroke. The 327 is 4inch bore and 3 and a 1/4 inch stoke. I had a 307 resurected into a 327 in my 57 Chevy Bigwindow Short Step. I had a 600 CFM edlebrock and a performer intake. I had the normal mid 80's 76cc heads on it and it ran great with great gas milage. Over 20MPG. Good luck with yours. JRB

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