Help! Asap!! 260 swap with 307 :(
January 14th, 2013, 09:19 AM
#1
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Help! Asap!! 260 swap with 307 :(
So i am doing an engine swap in my 79 cutlass supreme. i previously had a 260 v8 with a 2 barrel qjet. i am in the process of putting in the '85 307 that came out of a delta 88. i noticed that the wire harness is quite different than the one on my 79. im a noob at this but am willing to do what it takes to get my car running. The carb on the 307 used to have a computer, it is the stock 4 barrel qjet. MY MAIN QUESTION IS..will the '85 307 fit in my 79 with the same carb? i dont have much money and cant afford a new carb or intake. what do i do 
ANY ADVICE WILL HELP!! thank you
ANY ADVICE WILL HELP!! thank you
January 14th, 2013, 09:35 AM
#3
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Location: West Central Illinois
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I agree with Octania, but a little more passionately. The computer carb, might run without the computer, but in the aweful to horrid range. I would recommend a replacement. Also, do you still have the donor 88? I would be interested in the frame brackets for the engine mounts.
January 14th, 2013, 11:42 AM
#4
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January 14th, 2013, 11:44 AM
#5
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I agree with Octania, but a little more passionately. The computer carb, might run without the computer, but in the aweful to horrid range. I would recommend a replacement. Also, do you still have the donor 88? I would be interested in the frame brackets for the engine mounts.
January 14th, 2013, 08:15 PM
#9
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Location: Leasburg, NC
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I speak 100% from experince on this. I once swapped a 260 for a 307. And was SORELY disappointed. I know a lot more now than I knew then, and I should have went with a 350 or 403 no questions, hands down. Both of them will polt right into place.
as mentioned, use the distributor from the 260, BUT you may want to consider a recurve kit (basically changing the weights in the distributor) And yes, score that 4bbl carb from Octania.
but again.. unless that 307 was absolutely free and your 260 is blown and you are stuck without a ride..... step away from that swap
as mentioned, use the distributor from the 260, BUT you may want to consider a recurve kit (basically changing the weights in the distributor) And yes, score that 4bbl carb from Octania.
but again.. unless that 307 was absolutely free and your 260 is blown and you are stuck without a ride..... step away from that swap
January 14th, 2013, 08:26 PM
#10
Out of Line, Everytime😉
Join Date: Dec 2006
Location: Melville, Saskatchewan
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A pre 85 307 would have been a nice upgrade, I have owned several. The 85-up 307 swirl port, everyone complains of lack of power. It will be a small upgrade over your 260. If you insist, get the 350 carb, should be about right calibration wise.
January 14th, 2013, 09:21 PM
#12
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I speak 100% from experince on this. I once swapped a 260 for a 307. And was SORELY disappointed. I know a lot more now than I knew then, and I should have went with a 350 or 403 no questions, hands down. Both of them will polt right into place.
as mentioned, use the distributor from the 260, BUT you may want to consider a recurve kit (basically changing the weights in the distributor) And yes, score that 4bbl carb from Octania.
but again.. unless that 307 was absolutely free and your 260 is blown and you are stuck without a ride..... step away from that swap
as mentioned, use the distributor from the 260, BUT you may want to consider a recurve kit (basically changing the weights in the distributor) And yes, score that 4bbl carb from Octania.
but again.. unless that 307 was absolutely free and your 260 is blown and you are stuck without a ride..... step away from that swap
January 15th, 2013, 04:04 PM
#14
Just keep in mind about the 307,
81-84 307's had 5A heads and could be upgraded with ease, 85-90 307's were choked with AIR tubes and had smaller head ports for emissions. In other words, for crusing, you'll be fine, but for any upgrades in the future, you'll have to change over the the 5A heads, because there is nothing that will match the 7A (0142 casting) heads.
Also, boggie over to Home DEpot and pick up 8 1/4 inch pipe plugs in the plumbing department. Remove those AIR tubes and plug up the holes
81-84 307's had 5A heads and could be upgraded with ease, 85-90 307's were choked with AIR tubes and had smaller head ports for emissions. In other words, for crusing, you'll be fine, but for any upgrades in the future, you'll have to change over the the 5A heads, because there is nothing that will match the 7A (0142 casting) heads.
Also, boggie over to Home DEpot and pick up 8 1/4 inch pipe plugs in the plumbing department. Remove those AIR tubes and plug up the holes
January 15th, 2013, 04:25 PM
#15
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Location: Leasburg, NC
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Just keep in mind about the 307,
81-84 307's had 5A heads and could be upgraded with ease, 85-90 307's were choked with AIR tubes and had smaller head ports for emissions. In other words, for crusing, you'll be fine, but for any upgrades in the future, you'll have to change over the the 5A heads, because there is nothing that will match the 7A (0142 casting) heads.
Also, boggie over to Home DEpot and pick up 8 1/4 inch pipe plugs in the plumbing department. Remove those AIR tubes and plug up the holes
81-84 307's had 5A heads and could be upgraded with ease, 85-90 307's were choked with AIR tubes and had smaller head ports for emissions. In other words, for crusing, you'll be fine, but for any upgrades in the future, you'll have to change over the the 5A heads, because there is nothing that will match the 7A (0142 casting) heads.
Also, boggie over to Home DEpot and pick up 8 1/4 inch pipe plugs in the plumbing department. Remove those AIR tubes and plug up the holes
hope that helps a little more.
January 15th, 2013, 04:36 PM
#16
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thanks guys i will do that! and as of a stock '85 olds 307. what after market carb can i get for less than 300? i am willing to use a older non computer qjet but i cant seem to find one! i need one in working condition!
January 15th, 2013, 07:37 PM
#18
You CAN in fact remove those AIR tubes from the heads...however if you have a local pull a part yard, those 5A heads are still fairly easy to find. While you are at it, score a cheap A4 aluminum intake... also 84 or older 307 motors I beleive. they are RUMORED to be of similar performance to the Edelbrock Performer. I have no data to back this up, but being an aluminum intake in and of it self provides both a weight advantage and a heat dissapation factor that is better than cast iron.
hope that helps a little more.
hope that helps a little more.
In building an Olds motor, if you are running low on funds, an 81-84 A4 manifold is pretty much the same are the Performer 350 (3111) intake
January 15th, 2013, 08:39 PM
#19
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ANOTHER question guys! how hard is it to rebuilt a carb? an older non electronic QJet? i got alot of time on my hands and am fairly good at taking things apart and putting them back together. im driven to learn how to rebuilt it on my own since i dont got much money. HOW HARD IS IT?
January 16th, 2013, 04:07 AM
#20
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Join Date: Sep 2010
Location: The Hudson Valley
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It's easy.
Just make sure you've got plenty of time, a big, clean place to lay out all the parts (covering a tabletop with white paper will help you not to lose things, and let you make notes next to parts), and a high frustration threshold.
Read through the steps and operation description in the Chassis Service Manual or Rochester QuadraJet Manual once or twice with the carb in front of you first, and you should have no problems.
Basic kits are about $20 at the auto parts store, with another $10 for a float. You can get fancier kits from carb dealers on line for more, if that's your thing, but for a basic 307, I'd say save your money.
- Eric
Just make sure you've got plenty of time, a big, clean place to lay out all the parts (covering a tabletop with white paper will help you not to lose things, and let you make notes next to parts), and a high frustration threshold.
Read through the steps and operation description in the Chassis Service Manual or Rochester QuadraJet Manual once or twice with the carb in front of you first, and you should have no problems.
Basic kits are about $20 at the auto parts store, with another $10 for a float. You can get fancier kits from carb dealers on line for more, if that's your thing, but for a basic 307, I'd say save your money.
- Eric
January 16th, 2013, 05:05 AM
#21
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Location: Leasburg, NC
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It's easy.
Just make sure you've got plenty of time, a big, clean place to lay out all the parts (covering a tabletop with white paper will help you not to lose things, and let you make notes next to parts), and a high frustration threshold.
Read through the steps and operation description in the Chassis Service Manual or Rochester QuadraJet Manual once or twice with the carb in front of you first, and you should have no problems.
Basic kits are about $20 at the auto parts store, with another $10 for a float. You can get fancier kits from carb dealers on line for more, if that's your thing, but for a basic 307, I'd say save your money.
- Eric
Just make sure you've got plenty of time, a big, clean place to lay out all the parts (covering a tabletop with white paper will help you not to lose things, and let you make notes next to parts), and a high frustration threshold.
Read through the steps and operation description in the Chassis Service Manual or Rochester QuadraJet Manual once or twice with the carb in front of you first, and you should have no problems.
Basic kits are about $20 at the auto parts store, with another $10 for a float. You can get fancier kits from carb dealers on line for more, if that's your thing, but for a basic 307, I'd say save your money.
- Eric
I don't recommend using the basic part store kits anymore. The Walker kit, while inexpensive and very useable for a first build (Available at O'Rielly's or http://www.walkerproducts.com/produc...r-repair-kits/) it doesn't have ALL of what SHOULD be replaced.
I'm probably going to buy a kit from these guys (Cliff Ruggles) http://www.cliffshighperformance.com/carbkits.html#tab2 before I tear into my next carb build. They offer two kits priced, the stock build kit only $10 more than a parts store kit. Better quality and a few more parts in the box.
Dont forget to buy a new float and choke spring...
John
January 16th, 2013, 12:25 PM
#23
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Location: Leasburg, NC
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Like I tell my guys about the $99 per set of Pep Boys tires... sure get them, and you will replace them 4 times as more often than a quality $400 set of tires...
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