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norfla71's avatar
norfla71
Explorer
Feb 15, 2016

New TV purchased; seeking engine advice

Starting this to clear some internet clutter from many hours of research; I need to have a more clear focus for my budget, which will be about $4k all in for the motor. I really wanted a 6.6, but the engine alone is out of my range, and that's not counting potential future repair costs.


Just picked up a 99 Suburban C2500 about a week ago for dirt cheap (under $2k) with less than 200,000. Body is decent (needs paint) but is rust free and straight. Is has the L31 350, 4L80, 9.5 LS 14 Bolt with 4.10 gears and HD tow package. I could have gotten a V10 02 Excursion for about 1/3 more, but the guy sold it 2 days after I drove it, then I saw the Burb.

Year round road trip is still in the works, and we plan on paying cash for a TT that needs a bit of work. This will be temporary, eventually upgrading when the kids leave the nest. Considering the capacity of my rig, we'll be looking at under 30' and 7k gross, and there are tons of options in that range. Once the trans is rebuilt, and a few wear and tear items are addressed, this combo should pull fine for a few more years.

However, we want to upgrade to something with more heft, such as a Flagstaff V-Lite 30WRLIKS, just under 9k gross, and will need to upgrade the power plant to something with more beans if it's going to survive being worked FT. The base vehicle is there, and have no plans on replacing it.

So far I have quite a few options, and each would fit my needs: 6.0, 6.5, 454, HT383E, 8.1 or rebuild mine as a 355. I can find any of these second hand for relatively cheap money (maybe not the 8.1; I haven't searched yet). However, my biggest concerns are longevity, ease of repair and long term costs. Unloaded fuel economy falls in there somewhere, but not as important. We will be on a fixed income. I can wrench, and swap info is all over the net. If any more info helps, we plan on pulling just enough to get somewhere and stay for a spell.

Each engine has been out long enough that tons of info is available for any repairs or upgrades. Out of all of my options, and for my budget, help me narrow my options.

And before anyone asks the inevitable non-topic questions:
Yes, we will be buying a good quality WD hitch
Yes, we will be adding bags or Timbrens if needed
Yes, we may add a rear sway bar if needed
Yes, brakes will be upgraded
Yes, trans will be rebuilt or replaced with heavier duty version
Yes, yes, yes...

43 Replies

  • Always tough criticizing someone's plans, but if you have the budget for a 2k rig, 4K motor, trans rebuild, another 2k there, plus another grand or 2 for the other add ons you're talking about, take that 9-10k and buy something that works for you.
    You're throwing good money after cr@p. Not that 90s Chevies are ****, I think they're one of the best budget vehicles still on the road for reliability and ease of repair. But don't get into a hack job engine swap in a vehicle that is worth nothing to begin with. You'll have a mismatched pile of parts that your counting on hauling the family around the country that no one will want to work on if you have problems you can't fix yourself on the road.
    $10k will buy you a decent 2500 burb, Excursion or crew cab gasser.

    Or just run the snot out of the 350. I've towed a lot of trailers X country with Vortec and tbi 350s.
  • The L31 is a great engine in my opinion. I sold mine with 244k miles, and my low cylinder was 165!

    A mild cam, and tune would help you out while keeping the stock displacement (Black Bear comes to mind).

    If you have $4k for engine work or swap, sell the burb and get something else, like a slightly newer GM with an LS engine, or anything else with a little more displacement. Get used to locking out 4th any time the trailer is connected, and 2nd gear will be frequent on hills.

    Just remember that the L31 peak torque is at about 2800rpm.
  • The 6.0 and 8.1 will be a nightmare to swap from an electronics point of view. New gen of engine and emissions junk. The only word for the 6.5 is why?. It's a turd for power. The 7.4 won't give you enough difference to make it worth your while, I've towed with both.
    Keep what you have until it quits, or buy what you need now. Your intended mods will cost more than the right truck for your needs.
    Also, be aware that some states are getting picky about licensing OBD2 vechicles with engine swaps. Especially going backwards.
    I have been in your shoes when kids were in college, I would look for an older 5.9 Cummins or 7.3 PSD. There are plenty of them out there and they should live for many more years.