Junkyard 5.3 swap or rebuild the old 4.3, I flipped a coin and paid for it

I had my 1999 Silverado sitting in the driveway with a knocking 4.3 and about $1800 to play with. One option was a junkyard 5.3 with 140k miles for $650 out of a rolled Suburban, plus new mounts and a harness splice. The other was freshening the 4.3 with bearings, rings, and a cam kit for roughly the same cash but way more labor. I went with the 5.3 because the junkyard guy said it ran quiet, and two months later I'm chasing a weird misfire on cylinder 7 that turned out to be a cracked injector harness pin. My buddy did the 4.3 rebuild route on his S10 and it's been smooth for 6 months, so now I'm wondering if I just got unlucky or if the swap gamble is always a trap on a budget. Anyone else pick junkyard power over an in-frame rebuild and end up with a parts chase instead of a daily driver?

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miawalker11d ago

Take the 5.3 swap every time and don't look back. A 140k mile truck engine has way more life left than a 4.3 you're patching with bearings and rings, that old engine is still a 4.3 at the end of the day. Cracked injector pin is just a $20 connector and an hour of soldering, that's nothing compared to pulling a transmission and resealing an oil pan twice on a rebuild. Your buddy's S10 will be smooth until it ain't, and when a rebuilt 4.3 lets go it usually takes the cam with it. You got one bad wire, he got a ticking time bomb with the same money spent.