Swap or Build?

SBC or LSX?


  • Total voters
    18

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89Sport16

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All original 89 Sport, desperately needs more power! I want to get started by mid-Feb so the truck can be ready for Spring.

LSX is quick power, good MPG, but requires a lot more modifications to this original truck.

SBC build keep the original motor with less overall mods, but will the TBI need to be upgraded too? Seems like the costs can get out of control quickly.

What do you think, keep mostly original or modernize this truck with an LSX?

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New guys 1.5 cents worth-
I’ve got a 95 k1500 and have been struggling with the same question for 6 months. In short, if I had an 89 2WD, I would go LSX swap. The later model PCMs integrated transmission control and I believe some gauge functions which causes headaches with upgrading later models. The earlier models didn’t use an electronic transmission controlled by the ECM so there aren’t shift isssues to deal with. Manual trans are easier for swap based on research. Because of the increase in hp, you should consider getting the tranny with the donor and then it’s just a drive shaft length change. You can find LSX swap kits/mounts for a 2WD in many places. If you need a quick turnaround and can afford it, get a stand alone harness or turnkey motor. If you decide to rebuild the L03 or L05 with TBI, you’ll likely start chasing hp and torque and be more money into it than a swap and still needing a custom tune or tuning yourself. Either way, you have to upgrade fuel system for pressure increase for LSX or hot TBI. I joined this forum to search for answers to your same question, and everything I have found leads me to conclude “if I had an earlier 2WD or standard tranny - LS swap”. Guys on the forum that have actually done the swaps know considerably more than I do about this, but thought I’d share what I’ve determined based on months of research.
 

Blue91

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Id LSX swap it and if you use the 4l60e the driveshaft won' need to be modded because it' virtually the same as the 700r4 thats in it aside from being electronic. Then in the future you can boost it also and get hella power
 

89Sport16

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Id LSX swap it and if you use the 4l60e the driveshaft won' need to be modded because it' virtually the same as the 700r4 thats in it aside from being electronic. Then in the future you can boost it also and get hella power

Yeah, that makes sense, then I don't need to worry about the TV cable setup in the LS. I've been leaning towards both engine and trans if I do the swap.

Will a 4l60e out of a 4wd truck matter or do I need to find one from a 2wd truck?
 

Blue91

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Yeah, that makes sense, then I don't need to worry about the TV cable setup in the LS. I've been leaning towards both engine and trans if I do the swap.

Will a 4l60e out of a 4wd truck matter or do I need to find one from a 2wd truck?
Preferably 2wd but the tail housing and output shaft can be swapped from a 2wd to 4wd trans. LS motors and trans can be had for under $1000 and make great power with basic upgrades, and better fuel economy too
 

RickLSX

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LSX all the way, yes more wires, yes abit more work but these LS engines have almost double the hp/tq of any stock 350/454 in there stock form and have better fuel eco and tune-ability. I have a STOCK lsx in my 92 scsb, its out of an 2005 'vette, took the whole engine and harness. I went ahead and kept my stock nv3500 5speed transmission for the moment and swapped the clutch and flywheel for a 4.8 Ls v8 truck, it all bolted right up. I did however upgraded the rear end to a 14bolt with 3.73s and am getting very decent gas mileage and CRAZY power/torque compared to that 350 5.7 i had in it before that had headers, a cam, vortec heads and a chip. Whats fun about the stock LSX is that its pushing 400hp stock and you dont have to worrie about long road trips or the going to have fun with it at the drags or something. There are just as much parts for them as a 350, Id say almost more reliable than a 350. When it come to adding more HP its easy with simple bolt ons and a little tune to achive very noticeable power. If MPG's and more HP dont tickel your pickle then i dont know what stock 350 would.
 

89Sport16

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So I'm picking up a 5.3 w/ a 2wd 4L60e today. I guess now I need to make a parts list so I can get the fuel system, swap mounts, cam setup and AC mount since my current AC compressor is new. Also the 4L60e and 700r4 are similar, I don't think I need to modify anything, but I have seen cross-member kits for C1500 LS swaps, not sure if I need that yet. I'm pumped, can't wait to burn the over sized tires off this thing once I'm done with the swap!
 

89Sport16

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Knee deep in this swap, the motor and trans were pulled out last week, working on cleaning the engine bay and trying to figure out the wiring. So far I'm going through the existing harness to identify what needs to stay with the truck and what from the LS ties into the existing wiring. I'll get started on the fuel system once I get the engine bay ready.

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JLG88

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Build the SBC and convert to carburetor. I’ve done it a few times. Much simpler than dealing with computers and wiring for ls swap. We don’t build trucks to get good gas mileage. If you want good gas mileage get a Prius lol
 
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