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#1 |
Registered User
Join Date: Jun 2008
Location: Sacramento
Posts: 20
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Is a 4.8 Gen III motor to small?
OK guys,
I have a 4.8 and 5.3 with all the associated swap pieces to swap a gen III into my 67 truck. I am going to sell one of the motors, So my question is, is a 4.8 is too small for a 67LB 3/4 ton 4x4? The curb weight is probably just shy of 4500 lbs. I believe a standard 2wd 1500 is about 4000 correct? I also have a spare 5.7L crank, I could re ring and bearing the 4.8 with the rods and crank to make it a fresh 5.3, or .....should just put a LS1 cam, the headers in it and go? I am thinking it "should" have close to the same HP as a stock 5.3 with the headers and cam correct? Anyway, I have way to many Gen III parts and too may options! Here a list of parts, please chime in with some good feedback and give me some ideas. New 6L long block Bare 5.7L (3.905 bore) block with forged Diamond pistons Complete 4.8 Mid mileage Complete 5.3 Low mileage GMPP Carburated Intake GM Hot Cam Stock crank ARP main studs LS6 stage II or III heads (I forgot who's) Crower Maxlite 6.20 rods Stock 99 LS1 cam Stock 2000 Cam and 01 cam The 6L is going into my 67 Camaro with one of the 4l60's, main studs and the Stage II/III heads cam and a wet kit. The hard part is should I put the hot cam in the 5.3 and put it in the truck, or use a stock LS1 cam? Then should use 5.3 as it is and try and get a few $$ for the 4.8 or should I build the 4.8 as a 5.3, use it and sell the 5.3 as a complete motor? This is giving me a headache, Thanks. Mike |
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#3 |
Registered User
Join Date: Sep 2006
Location: cedar bluff,al
Posts: 29
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Re: Is a 4.8 Gen III motor to small?
Build the 4.8 as an iron LS1 , use the rotating assembly out of an ls1 which means you will have to bore it to ls1 bore. Use a 224-226 duration cam with about 585-600 lift and you will have a dayum good running motor. Rotating assemblies can b found for cheap on ls1tech.com
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#4 |
Senior Member
![]() Join Date: Oct 2005
Location: south carolina
Posts: 658
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Re: Is a 4.8 Gen III motor to small?
I agree with sandking.
__________________
1972 chevy cheyenne 10,nothing special at the moment,Its a work in progress, Working on the engine, paint and body,engine, paint and body,now its the suspenion, ahh hell I'm about tired of working on it. Maybe it will be a rat rod. ![]() |
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#5 | |
Registered User
Join Date: Jun 2008
Location: Sacramento
Posts: 20
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Re: Is a 4.8 Gen III motor to small?
Quote:
Or I could bore either one and use the 3.905 bore pistons and have a iron block 348 without the block distortion...lol. I wanted to keep the CID down for mileage purposes. (Even though it really won't make that much of a difference.) If this was going into something were hp was a priority then I would (or I'd go (use) 6L) but it is mainly a camping and utility truck for hauling around the quad and occasional towing of the car trailer. Reliability and mileage are the key points,...iron block gen III's seem to last a bit longer than aluminum block motors, especially when it comes to any rebuilds. |
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#6 |
Senior Member
Join Date: Aug 2002
Location: Valley Center KS
Posts: 3,525
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Re: Is a 4.8 Gen III motor to small?
I'd sell the 5.3 and bore/stroke the 4.8 to a 5.7L.
I have a similar (but not quite as many options) as you. I have a 5.3L in my truck now, but also have a LS6 block on a stand that is missing a piston and rod (PO bent a rod). I got a set of stock LS1 pistons, so I can rebuild the LS6 or bore the 5.3L. Don't know what I'm going to do, but I'm running the 5.3L for now. |
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#7 | |
Senior Member
Join Date: Nov 2005
Location: AL
Posts: 2,519
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Re: Is a 4.8 Gen III motor to small?
Quote:
It was a driver so it wasn't the best looking install but it served the purpose. I would build another one of these in a heart beat, you can pick up used ls1 internals dirt cheap. The 5.7, 5.3, and the 6.0 all have the same crank and just find some 5.7 rods, pistons, and use the stock 4.8 heads. ![]() ![]() Last edited by jkade; 09-29-2008 at 08:28 PM. |
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#8 | |
Registered User
Join Date: Jun 2008
Location: Sacramento
Posts: 20
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Re: Is a 4.8 Gen III motor to small?
Quote:
I really don't want a high hp or maintenance motor,...just a strong small cid gen III with decent tq to get us up and down hills. And to give us something better that the 9 mpg the current carbed 327 gives. ![]() |
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#9 |
Registered User
Join Date: Jun 2008
Location: Sacramento
Posts: 20
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Re: Is a 4.8 Gen III motor to small?
Nice!
We also have a 68 2wd SB that may be going up for sale, I was thinking of putting the 4.8 in that with the LS1 cam, dual exhaust and a set of 20's I have laying around just to get a few more $$ out of it all. But that's just more options. I want to consolidate all my damn projects and do it as economical as possible. I am liking the sound of the rebuilt 4.8....I may put the 5.3 in my 3/4 ton and rebuild the 4.8 then swap it. I can't believe how cheap you can get (or have to sell a) 4.8 for!!! |
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#10 |
Senior Member
Join Date: Nov 2005
Location: AL
Posts: 2,519
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Re: Is a 4.8 Gen III motor to small?
[QUOTE=Hallz;2909666]I have the crank and access to stock rods prity much all day. The only difference from a 4.8 to a 5.3 is the stroke,...and from the 5.3 to a 347 is the bore. Both the 4.8 and 5.3 share the same block and bore,...and the 5.3 and 5.7 share the same crank and rods,
Correct. Mine would still get 15mpg + with what I did. It ran great and was as reliable as a stock motor. I wouldn't perfer a stock 4.8 over a 5.3 if they were both going to be stock, one really doesn't run better than the other stock. If you have access to the 5.7 intrernals I would do that and have a bad little motor that will still get good mpg and run better than most $4000 genI sbc's. |
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#11 |
Senior Member
Join Date: Aug 2005
Location: tulsa OK
Posts: 3,070
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Re: Is a 4.8 Gen III motor to small?
ive done a stock internals, 5.3l, with headers. air intake, and a tune....it had 300RWHP amd 320 TQ......so those 5.3 arnt too bad for power.. id say do the 5.3 with mild bolt-ons, it'll be good on MPG and decent on putting around
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#12 |
Registered User
Join Date: Aug 2006
Location: Georgia
Posts: 850
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Re: Is a 4.8 Gen III motor to small?
Use the 4.8 and you can give me the 5.3 as an early Christmas present.
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#13 |
Senior Member
![]() Join Date: Sep 2005
Location: Lewisville, Nc
Posts: 10,234
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Re: Is a 4.8 Gen III motor to small?
just a friendy reminder any selling will get this thread locked
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David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube |
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#14 | |
Senior Member
Join Date: Nov 2005
Location: AL
Posts: 2,519
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Re: Is a 4.8 Gen III motor to small?
Quote:
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#15 |
Registered User
Join Date: Apr 2008
Location: Houston, TX
Posts: 247
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Re: Is a 4.8 Gen III motor to small?
i have also had both and for the the 5.3 has always felt way stronger, no need to do all those internals, a stock 5.3 with that hot cam will work real good!, the LS1 cam swap will not be worth your time and wont notice the difference.... let us know how it goes... im also in the process of putting a 5.3 L33 in my 68 which has very similar heads to the LS6, and i will be installing a 226 cam in there since thats what i have laying around,....
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1971 C-10 SWB - LS swap w/4L60e, 20x8.5front 20x12rear, 1968 C-10 SWB - 454 BB TH350 -Gone! |
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#16 |
Skinned knuckles
Join Date: Oct 2006
Location: Longview, Washington
Posts: 1,126
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Re: Is a 4.8 Gen III motor to small?
Man, you guys are making this sound really fun!! Someday I'd like to go with a Gen III in mine. I had the 4.8 in my 02 Silverado and really liked it. Being a 4wd X-cab, that little motor had had plenty of power to move it with the 3:73's.
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'72 C-10 longbox soon to be short step! '72 Chevelle (sold in January) ![]() '07 Sebring '01 Ranger (I've gotta long commute..) If you try to fail, and succeed, which have you done? My build thread - http://67-72chevytrucks.com/vboard/s...d.php?t=276904 |
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#17 |
Questionable
Join Date: Mar 2005
Location: Atlanta
Posts: 13,376
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Re: Is a 4.8 Gen III motor to small?
i'd be totally happy with either a 4.8 or 5.3, either one is a significant improvement over any 350 SBC or crate motor you'll put in your truck.
i feel like people get WAY too critical over this kind of thing. if you put a GenIII engine in your truck, it really doesn't matter a damned bit which you put in your truck, they're all going to be better and more efficient than 90% of the other engines you could stuff in it.
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If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (link) I can't check the forum daily. If I don't reply to you within 24 hours, drop me a PM! I'm (hopefully) still alive and will reply faster to a PM. |
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