Is a 4.8 Gen III motor to small?

[Hallz]

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

[sandking]

I would sell the 4.8 and the 5.3 then buy an LS1 with the money and be done with it.

[1969x11]

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

[roughedup72]

I agree with sandking.

[Hallz]

Originally Posted by sandking

I would sell the 4.8 and the 5.3 then buy an LS1 with the money and be done with it.

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.

[Ackattack]

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.

[jkade]

Originally Posted by 1969x11

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

What he said, I bored the 4.8 out of his 99 silverado and made it a iron ls1 and put in stated cam. Lets just say it was a handful to keep between the ditches. I put this in a 67 c10 with a 4l60e, 20's, 295/40/20's, and a locker and it would just boil the back tires off as long as you stayed in it.
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.

YouTube - 67 C10 LS1 Magnaflows

[Hallz]

Originally Posted by 1969x11

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

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,

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.

[Hallz]

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!!!

[jkade]

[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.

[68 short step]

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

[Chevyman680063]

Use the 4.8 and you can give me the 5.3 as an early Christmas present. I use to work at a dealership and got to drive Silverado's and Sierra's all the time with the 4.8 and 5.3. I loved the 5.3's because when you stomped on the gas it would spin some tires but the 4.8's would bog down when stomping on the gas. I'd go with the 5.3 but there's nothing wrong with the 4.8 either.

[truckdude239]

just a friendy reminder any selling will get this thread locked witht hat said the 5.3 is a storng motor as is the 4.8 i'd build the 5.3 and swap it in myself

[jkade]

Originally Posted by Chevyman680063

Use the 4.8 and you can give me the 5.3 as an early Christmas present. I use to work at a dealership and got to drive Silverado's and Sierra's all the time with the 4.8 and 5.3. I loved the 5.3's because when you stomped on the gas it would spin some tires but the 4.8's would bog down when stomping on the gas. I'd go with the 5.3 but there's nothing wrong with the 4.8 either.

I hate to disagree, but a 5.3 doesn't really run better than a 4.8 when the gear ratio is the same. I used to sell chevy's and I drove every truck on the lot and the 5.3's did seem to run any better than the 4.8's. I bought a 99 gmc new with a 4.8 after driving the same truck with a 5.3 and I couldn't really tell any difference. Now if you are modding these motors a 5.3 will take to them better than a 4.8 and then the 5.3 will shine. Not trying to start a argument but I have owned them both. It is not like a 305 compared to a 350 in my opinion, the 4.8 and the 5.3 are both great motors. That being said I would spend another $100-$200 just to buy a 5.3 because I would mod the motor. JM2C and you won't go wrong with either. If you are going through all the trouble to install a genIII motor you might as well do a 6.0 and be done with it if you are having to go out and buy a motor, but if you already have one then use it.

[ap2002]

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,....

[Blue'72]

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.

[shifty]

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.