just something i'm thinking about so i thought i'd put it up to the CF gods and see what comes of it.
i have an '06 GMC 1/2 ton that's about a year and a half old now. when i got it, i specified the towing package because i knew that i would be towing my car from time to time.
now it looks as though i'll also need to tow a boat from time to time as well.
the 5.4L that comes in the 1/2 ton towed my c3 on a trailer across the mountain pass pretty well but i suspect it's not up to the task of dragging a 10,000# boat out of the lake
SO,
instead of starting all over with a new loan for a new truck that is more than i need and more expensive than i want to pay for, my option is to mod this one.
my thinking is buy a set of corvette LS1 heads from here on the forum. it seems they go pretty easily for $100-200. find a 6.0L short block and install an RV grind cam. the intake, injections, exhaust and accesories should all pretty much bolt right up. i'm thinking heads, cam and shortblock i can probably swing for around $2k.
the whole swap would be pretty straight forward and then all i should need is to stiffen up the rear springs to handle the extra weight.
i believe the tranny that's in there now is the same one available with the 3/4 ton tow package so that shouldn't be a problem and i don't think i'd need to do anything different with the axle.
this will be primarily to tow a boat 15 miles from my house to the lake and back maybe a dozen times a year.
obviously, there is a warranty concern with this. the engine will certainly be voided but i don't know what, if any, impact it would have on the rest of the drivetrain.
then again, there's always going further into hock to buy more truck than i want and need.

 

The 5.3 will pull a heavy boat just fine... My grandfather has a 28' Glacier Bay and he pulls it all over the place with his 5.3 powered suburban.

 

I pull alot of weight with my 5.3 sierra. If i were you i would put a cold air intake, exhaust and a ls6 stock cam in there. That would surely do it. There are a few LSX books out there that will give you great info.
good luck

 

i've been wondering if something as simple as some 1.7 rockers and headers will give me enough oomph to do what i need to do. of course, a cam swap would be pretty easy to do also. maybe an LS6 intake too. i dunno.
honestly, i'm so impressed with this little truck i don't think i would have that much trouble once i got the boat out of the water. the ramps are what really worry me. especially not being 4x4, but no headers or cam will help that.

 

For that short of a trip you should be okay with the stock engine, any changes would be some tri-Y headers for extra torque, and to the trans, 4L60E, you should add corvette servo and billet OD servo.

 

Any of the above....1.7 rockers, LS6 intake etc, etc, etc will do nothing to help pull a boat out of the water on a ramp. In fact, higher-ratio rockers will kill low-end torque which is what you need for towing. Going to the LS6 intake won't do **** as the 5.3, even with rockers, won't rpm enough to use the extra flow. In fact, the LS6 intake has a shorter runner length than the stock, truck intake, so, again, you're going to loose low-end torque.

With the 5.3, there's not alot you can do to improve torque output where you need it for towing, ie: the low-end and the mid-range other than putting a roots type blower (ie: the Magnuson) on it or adding a 6.0L short block.

If you still want to mod the 5.3, I'd look at very modest head work, ie: no increase in port volume or valve size, but polishing, porting valve pockets a little and three-angle valve jog--headers and recalibration for 92-octane gas. You also might look around for an "RV" cam profile but be very careful doing that. Most of what you're going to find out there is aimed at high-performance because the stock camshafts in the truck engines are pretty good for towing.

Lastly, looking past the engine...an axle ratio change will definitely help you pull boats up the ramp. I'd go up (numerically) one ratio. That is, if you have 3.42s go to 3.73s. If you have 3.73s go to 4.10s. but, keep in mind, the axle change will decrease gas mileage.

 

Good grief, just what kind of boat are you pulling?!?!?

First boat I ever owned was a Supra Sunsport, an inboard barge that could hold 8 people and still jerk a competition slalom out of the water. Of course, top end was about 40 .

Total weight of that boat+trailer was around 4,000 lbs; we pulled it around with a '92 Crown Vic that I put air springs and an external tranny cooler on.

10K pound class is getting way, way, up there. What are you intending to do about stabilizing the thing so it doesn't shove you around when you hit the brakes, turn at an intersection, etc.? (I learned that lesson the hard way... )

HTH, and have a good one,
Mike

 

The LS6 cam is designed to make high RPM power. My friend put one in a Silverado SS and his truck was actually slower from lack of low end power.

The LS6 intake will not fit, since it has shorter runners (designed for high rpm power) it is not as tall, and the installed height of the throttle body will not clear your 5.3 bracketry on the front of your engine.

 

25' carver flybridge.
thanks for the advice so far guys. looks like i was closer with my original idea. 6.0L shortblock with a set of LS1 take off heads and an RV cam should provide plenty of oomph to do what i want to do. or maybe even forgo the LS1 heads and bolt the 5.3L heads on there and do a set of headers instead.
hey hib, good to see you're still lurking around. you still have the BBFH?

 

OMG! that boat weighs 5T? That is unbelieveable!

At least it is only 15 miles

I tow a 26' 4W 260 H with my 04 Suburban k2500 8.0L

With K&N intake, Gibson exhaust and a tune, I still wish I had another 100 HP & Ftlb.

I go abt 200 Miles to Lake Powell through the mountains however.

Good luck with the 5.3

RG
AZ

 

Yep.
But, recently, I "broke" it.

It's back at my shop in California with the motor partially disassembled. After 12 years, I broke the #8 exhaust lifter. Fortuantely, I caught it really quick and the cam lives. Soon as I get back, I'm going to put a new set of roller lifters in #8 along with new pushrods and valve springs then do to the chassis dyno. After that, I'm swapping the 12-year-old "Red Rocers" for Crane's new shaft rocker system for Big-Blocks.

 

If you want to go through all that trouble, it would be easier to just buy a GMPP 6.0L Escalade engine and drop it in. I recently did a conversion on a customers 1/2T pick up that originally came with a 4.8LS1. Talk about anemic, that 4.8 was exactly that. I also installed a set of Dynatech headers, a small LPE GT2-3 camshaft, springs and dyno tuned the combination. He has 3.73s for gears out back and the truck ran great! It made 330 to the rear tires and was a HUGE improvement in TQ over the stock engine. I stock form the truck struggled to make 220.

 

We did the same thing in my friends truck... he has an 03 silverado he decided to drive through 4 feet of water one day and hydrolocked the engine. I had an LQ9 that I bought as a takeout from Livernois, it had like 12 miles on it. We swapped that in place, and swapped his 4L60e to a 4L65e, and that thing SCREAMS now! For a truck at least, it's pretty beastly.

 

I'm not a supercharger guy---but wouln't it be easier to throw on a procharger or maggie on your existing engine ?? I think going from a 5.3 to a 6.0 would require pretty much a full flash of even a computer swap-- the files are so different--Just a thought--Don't really know what you can buy a S-charger for--

 

i'll check into the blower idea. it is always a thought. i stopped into the local chebby store today just to check and they don't even sell a 6.0L shortblock, only long block. that makes things a little more expensive.
don't really know about the computer. i wouldn't think it would be that huge an issue. i can see maybe having to tune it but don't know about much more than that.
i'm just knocking around ideas right now. i really don't want to have to spend any more money on a new truck. it kind of pisses me off that i had to buy one anyway. if i had a choice i would never own anything with more than 5" of ground clearance!