HELP! Swap in a Vortec 8.1 or build my 5.3??

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blackjack

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Not to shit on you or anything but my Silverado towed my Buick and trailer (6k) no problem bone stock and I live at 6k feet. I think rear end gears would make a much bigger difference for you than a cam for towing. My truck had 3.73’s
My Tahoe PPV with the Cam has 3.73's also...
I forgot to mention that to "Pilot"...yeah, he gotta go that...his may have 3.42 or 3.08 who knows....
not that big of a deal unless its a 4x4
 

Ilikemtb999

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My Tahoe PPV with the Cam has 3.73's also...
I forgot to mention that to "Pilot"...yeah, he gotta go that...his may have 3.42 or 3.08 who knows....
not that big of a deal unless its a 4x4
3.08-3.42-3.73 makes a big difference regardless of 4wd or 2wd.
 

Ilikemtb999

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Oh I thought you meant gear ratio differences didn’t matter if 2wd lol.

4wd isn’t hard if you find the entire diff. That’s an easy swap.
 

bottomline2000

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If you want the best of both worlds I would pull the 5.3 and put a forged 6.0 or bore to 370 and put the biggest Magnusson you can find on it. You can pulley down that blower with the right fuel setup make North of 700hp. Plenty of low end grunt..You could pulley down and add fuel as you grow. The replacement for displacement is FI. It would be unique only because of the power output though.

You could also do a trick turbo kit and build the 5.3. You would have crazy power potential.

I would do a 4l80 with hard parts and triple disc converter with a low stall so you can tow comfortably. I'm not sure how much power the stock converter can hold and no reason to leave a weak link.

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adriver

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I should be getting my Tahoe back from the paint shop soon and now I want to start thinking about performance mods. It’s an ‘02 5.3 L59 (don’t know if the block is iron or aluminum) with 200k miles. Here are my goals:


1. A spectacle: I’m not into the whole “sleeper” thing. I want this thing to stand out
Then paint it pink with lime green stars. Put a taxidermy leopard on the hood and 14 purple ****** sticking out of the grill (just so people get out of the way). Were talking about an engine right? Not sure what you are trying to have stand out.


2. Ridiculous: I’m the king of overkill. I want this thing to be unique and over the top. My baseline goal for phase 1 is 500 whp but a platform that I can continue to build on, just as long as I can reasonably achieve number 3, which is...
FI. Build it up right, spend the extra money, and you will be able to go from 500 to much higher with very little (relatively). OR, you could be one of the few that might want a …………..


3. Value: I’m willing to throw some money at this build so long as I get reasonable HP/torque gains in return.
FI. Spend the extra money, build it up right, and plan for higher boost from the start.


4. Low end: I want this thing to launch off the line with solid torque throughout the entire band. I don’t want a high revving motor whose torque kicks in at 3500. I also want to be able to tow a nice size load.
That's supercharger not a turbo, OR...……….


5. Daily driver manners and reliability: I don’t plan to take this to the track and I don’t want a finicky truck. I just want it to be a blast to drive on 91-93 pump gas.
Supercharger, OR...……….


6. Gas mileage: I mean, come on..
But how bad are you willing to be? Is this a daily driver, that you are cool with cutting your tank range in half, or can we get past the 8.1?


So that isn’t too much to ask for, right? Lolz


I’m tossing around the idea of swapping in a used Vortec 8.1 with a Raylar stage 2 head/cam/intake kit. That should produce 525 hp with 585 tq naturally aspirated. Then I could add a Raylar (Whipple) supercharger later in phase two.
For me, its the mileage thing. I'll stop bringing it up, but you should at least figure out how many miles you drive a year, figure out how much you have spent in fuel, and then double it. That's partly to do with you putting your foot down more.


I know there isn’t a huge community around the 8.1 like there is the 5.3, but there does seem to be a cult following. Plus I just think it would be cool—you don’t see many 8.1 Tahoes.
There is a reason for both of those things. As said by another poster, Do you want to utilize the engine technology of the old-school racers from the 60s (that were getting 8mg and about 130-150hp from big blocks), ORRRRR... Do you want to utilize the Gen III/IV+ LS engine crowd racers (camaros, corvettes, firebirds, trans ams, LS1, LS2) that have done what you want. you can use to upgrade your parts such as using Gen IV rods to upgrade the Gen III rods. There is SO much more that's been done, that's going to be cheaper, quicker, more reliable, and readily available.


The downsides are my gas mileage would SUCK, I would be more limited on both GM and aftermarket parts, and it’s definitely not cheap. I’m anticipating 2k for used motor, 6k for Raylar build, $2k for ancillary/labor. And that’s before I get into the exhaust or transmission (I’m thinking I’ll swap in a 4L80?).
That's more than a 5.3 or 6.0 build would cost. I would expect a 5.3/6.0 to be more reliable



Or could I check most of my boxes for far less money by building out and supercharging my 5.3? I’m concerned that it has 200k on it. I want this thing to last forever! How do I know if it’s in good enough shape to invest in?
YES you could. Take it to an engine builder and have them do it. Or even better have one built up and installed. SPEAKING AS SOMEONE WHO CAN NOT DO IT, HAS NEVER DONE IT, AND PROBABLY NEVER WILL, (I'm only half-full of shit if I admit it up front), but swapping an engine should only take about a day once its ready. Then sell the (did you have a 5.3?) for I see them about $750-$800 complete.


I’m obviously pretty clueless. Any input is much appreciated.
ORRRR... You could always STROKE IT.. There are better ways to do it, but this might be what you want? Really depends on what your goals are and what you end up finding to be more important. If you are this unsure, I would suggest researching some local engine builders. See if there is someone you know you want to go with, and try talking to a few of them. (Not sure if anyone on here is or not). We all know the 8.1 should have the most low end torque, but I think you're giving up a lot, and hope you compare those graphs and see several torque curves so you know what the difference truly is.

http://www.trucktrend.com/how-to/engine/1208tr-5-3l-bow-tie-builds-mild-to-wild/


Heck, you can buy performance engines right off so many places, and just have something swapped in. Summitracing, jegs, Even Autozone carry performance engines. Have you at least gotten some ideas off there?

If you plan on doing the trans too, there's got to be a performance drop in for an engine and trans combo or find a low mileage pullout from somewhere.


For what it's worth, I vote 8.1. I love mine in my suburban. There is not a ton of aftermarket support for it without some deep pockets. But it is a low end torque machine and runs amazing for what it is on my Blackbear 91/93 tune. GM performance finally offers a conversion kit to mount a 6l90 to it as well if you want a true one of a kind build. There is a Facebook group run by Edward Coss dedicated to the 8.1. He is a wonderful resource for all L18 questions.

Just curious, what do you get mpg?
 
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