s34n

instead of buying a new truck.. what about getting a 5.3 motor? the gears are fine in ratio with everything else. im not positive about the supercharger either. but maybe price out a motor and see what it would cost.

MathewsMan

Yeah I thought about just buying a motor but didn't know if that would cause more problems and just figured it would cost more. Are all the parts pretty similar? I am not mechanically inclined when it comes to car motors. Maybe the gears would be fine if I had a 5.3L V8. Anyone know about what the cost and where to get a 5.3L?

MathewsMan

Another thought is what would it take to have this 4.8L converted to a 5.7L, if that is even possible?

LARIDERS

I like my supercharger. I don't have any problems with heat and pull and very big heavy trailer. they cost alot, not to hard to put on. they will give you alot of extra go ,but remeber it still won't be a race car.

therewolf

Hi Matthews Man,

Welcome to the Chevy Forums.

Okay, hold the phone here.

First, running the cruise control in hilly country is a BAD IDEA. Even with no load whatsoever, you're going to have the high revs when the CC tries to maintain speeds EXACTLY on upgrades.

Second, the 373s are a great general-purpose gear. Going to 410s is going to increase your revs overall, and run your engine much harder at highway speeds. I installed 342s to get away from the outrageous revs my engine was pulling at highway speeds with 410s.

Third the cost of new gears and bearings is @ 2000$ out the door. But be sure the shop reflashes your PCM so your ABS sensor doesn't go nutz, and your speedometer still registers the proper speed with the new gearing.

Fourth, even if you get a new differential gear set, your CC is still going to rev high on upgrades, because it's not compensating for agregate mileage or keeping a general speed. It's trying to keep your speed very exact, which is almost impossible in hilly terrain.(So you'd lose out twice,with the higher revs of the new gears, and the correspondingly poorer MPG)

I would recommend considering to try driving with the CC off for these trips, in order to lower your RPMs. Your engine can probably pull the load just as it is, if you don't run Cruise -Control in the hills. Then you could spend the money on cool new stuff for your boat, or even cooler stuff you really need for your truck.

.

s34n

the gears are fine with a 4.8 as well. thats why they are on your truck.lol. pending on what supercharger you get, the price for the motor and charger may be comparably the same. the wiring harness should be the same. i dont see why they would change between motors. but i could be wrong.
most of the internals are the same with the exception of head size and compression ratio.

i have an 04 1500 with the 5.3L and 3.73 gears and it is pretty powerful stock. at 70 mph it revs at 2k rpms. at 75 its about 2500 rpms.
i think a new motor would be beneficial.

i would stay with your gears because its not too high of a rev and not too low and has good torque.

MDTAHOE

I would look into a Black Bear custom tune. Contact them and see what they can do for you. It will be the most economical thing to do.

MathewsMan

Wolf and 34n great advice I really appreciate the input. I actually took the truck off cruise and I could not maintain speed with out the truck rpms jumping. I was like running on flat ground the rpms are at 2500 then on slight increases it jumps to 3500 which all feels right then on steeper hills it would hard shift to 5500 rpms.

It sounds like the 3.73 gears are fine so is it just the horsepower that needs to be increased? I mean if I were hauling 10K or something I could see the problem but man this is a 17' flat bottom boat. Granted I did have the cab and bed loaded as well but I had no idea the 4.8 would struggle so much.

So what would you guys recommend I do to get the 4.8 to perform like the 5.3 or even 5.7 outside of buying a new truck? Is there anything or do I just learn to live with this motor until I can get a new truck. I will say one thing this is the last 4.8L V8 I will ever own.

s34n

like therewolf said, on steep inclines the truck will downshift into 3rd gear to keep the same speed thus consuming more fuel its the way the new computer controlled motors are. i agree with mdtahoe and the tune. checkout blackbearperformance.com i've talked with a guy on here who loves his tune. he said it has opened up the true power of the motor and is impressed. but to start cheap do the tune. programmers dont even compare to the tune. so email the guy and talk to him about what he can do for you.

MathewsMan

I have heard a lot about BB tune but didn't really think it would make a huge difference since I already had a new exhaust, cold air intake and bully dog programmer put on the truck. Sounds like I was wrong. That would certainly be a less expensive way to go for sure.