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BigBlocksRule · 09-16-2010, 07:23 AM

Keep in mind that if you keep the 5.3 injected, you'll need speed sensor inputs from your tranny along with a few other things. MSD makes a box that'll run it carb'd, but you'll need TPS, VSS, etc. also. You'll probably want to use the donor tranny to make it a lot easier, IMHO.
Unless you have access to someone who knows what they're doing with injection or you can pull EVERYTHING from the donor truck, you'll probably be better off sticking with the Vortec, it's an easy carb/distributor swap. As for the injection and swap paying for itself over time, it depends on how much you drive the truck. I know a lot of folks with the 5.3 and 5.7 that get no better mileage than a well tuned 5.7 Vortec. Even if you pick up 2 - 5 mpg, that'll take a long time to pay for the investment.
I won't mess with LS swap with anything smaller than a 6.0L, just not worth it IMHO. Now take a 6.2 with those big square port heads, stroke it, and then you REALLY have something!!!

09-16-2010, 07:23 AM	#14
BigBlocksRule Registered User Join Date: Jun 2008 Location: Lubbock, TX Posts: 2,047	Re: Got a Vortec.... Keep in mind that if you keep the 5.3 injected, you'll need speed sensor inputs from your tranny along with a few other things. MSD makes a box that'll run it carb'd, but you'll need TPS, VSS, etc. also. You'll probably want to use the donor tranny to make it a lot easier, IMHO. Unless you have access to someone who knows what they're doing with injection or you can pull EVERYTHING from the donor truck, you'll probably be better off sticking with the Vortec, it's an easy carb/distributor swap. As for the injection and swap paying for itself over time, it depends on how much you drive the truck. I know a lot of folks with the 5.3 and 5.7 that get no better mileage than a well tuned 5.7 Vortec. Even if you pick up 2 - 5 mpg, that'll take a long time to pay for the investment. I won't mess with LS swap with anything smaller than a 6.0L, just not worth it IMHO. Now take a 6.2 with those big square port heads, stroke it, and then you REALLY have something!!! Last edited by BigBlocksRule; 09-16-2010 at 07:35 AM.