94 GMC 1500 4.8 swap
08-10-2011, 07:26 PM
#1
94 GMC 1500 4.8 swap Well, i have been planning this for a bit, the old 350 TBI is having issues with the electronics somewhere, and rather than fix it, i want to install a 5.3, going to look for another 07 up model, maybe do a LS6 cam while i am at it, if not it will stick with the stocker.
It sill be a Performer intake, 750 Holley Vac sec, 4L60 from whatever i find that is 99 up, the trans controller from FAST is on the way, waiting till i get a motor before i get a 6010 or 6012, learned my lesson on jumping the gun on a ignition controller.
I have Schofield headers for a direct LS swap on the way as well, 1 3/4 full lengths W/3 inch collectors. Going for 22 MPG on the freeway, my 4600 pound Trailblazer does it with the lower compression 5.3(03 model), so the truck being 4200 pounds and assuming i score the newer 5.3 that will make it move a bit easier, i think it will work fine.
I do have a posi unit i need to put in the truck that i have been sitting on, i am willing to be this new setup will require me to install it since the 300K mile 5.7 that makes 190 HP is just paling in comparison.
Stock the newer 5.3 make 320 HP or so, but a article using the older 5.3 was 337 hp and 351 lb-ft of torque with a carb and headers, GMPP intake, so i assume the single plane will make allot more torque and make the drivability better, and a LS6 cam would be the icing on the cake making an additional 20-25 HP.
So i am assuming 370 HP from a mild 5.3 and the torque will be somewhere around there as well.
Here is said truck:
It sill be a Performer intake, 750 Holley Vac sec, 4L60 from whatever i find that is 99 up, the trans controller from FAST is on the way, waiting till i get a motor before i get a 6010 or 6012, learned my lesson on jumping the gun on a ignition controller.
I have Schofield headers for a direct LS swap on the way as well, 1 3/4 full lengths W/3 inch collectors. Going for 22 MPG on the freeway, my 4600 pound Trailblazer does it with the lower compression 5.3(03 model), so the truck being 4200 pounds and assuming i score the newer 5.3 that will make it move a bit easier, i think it will work fine.
I do have a posi unit i need to put in the truck that i have been sitting on, i am willing to be this new setup will require me to install it since the 300K mile 5.7 that makes 190 HP is just paling in comparison.
Stock the newer 5.3 make 320 HP or so, but a article using the older 5.3 was 337 hp and 351 lb-ft of torque with a carb and headers, GMPP intake, so i assume the single plane will make allot more torque and make the drivability better, and a LS6 cam would be the icing on the cake making an additional 20-25 HP.
So i am assuming 370 HP from a mild 5.3 and the torque will be somewhere around there as well.
Here is said truck:
08-15-2011, 07:27 PM
#5
LOL, man, this is the last SBC powered vehicle i own, and i am not happy with it, so be gone and replaced by the more efficient newer stuff.
Pretty funny, it gets 16ish MPG with the TBI motor, with the carbed 5.3, i should be getting 22.
Pretty funny, it gets 16ish MPG with the TBI motor, with the carbed 5.3, i should be getting 22.
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08-21-2011, 10:02 PM
#11
Well, noticing a popping sound spinning the motor over by hand, i removed the intake and manifolds to see valves are sticking evidently due to being bent, so i am taking it back to the JY and swapping for a different motor, they had one more 4.8 so they should swap me with no issues. If there is a 5.3, it is all me.
08-22-2011, 11:08 PM
#12
Well, went to return the 4.8 to get another, or a 5.3, ended up swapping the 4.8 out and buying the old one back for 200 as a core with a couple bent valves on the 243s, LOL. So, a 2009 4.8 is going in.
So it begins, started taking the old TBI 350 apart, still need to take the DS out and then remove the motor and trans and prep for the new setup to go in.
So it begins, started taking the old TBI 350 apart, still need to take the DS out and then remove the motor and trans and prep for the new setup to go in.
08-24-2011, 03:16 AM
#16
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how are you breaking the bolts? ive never broken one head bolt and ive built over 100 ls engines. when you use your torque wrench do you not set it back to 0 after use? or are you over torquing when going on the final pass? if your not zeroing your torque wrench when done on your final pass they could be way over torqued.
08-24-2011, 08:31 AM
#19
Back in the day, when I worked on older rustier stuff, we used too whack the top of the bolt head with a hammer and punch before loosening it. I am not sure that is a good idea on a head bolt seated in a cast iron block. I would speculate that with cast iron you could break the threads in the block and that would not be a happy day.
08-24-2011, 12:45 PM
#20
Using the correct stretch toque gauge, it probably would not have happened, a friend did it on his 6.0, the one that did not end well with FelPro bolts, mine was with GM bolts, it did not seem to want to tq down, i set mine back to zero always when using it.
Yea, i did not know i was going to be removing heads, so i was unprepared and wanted to get it together ASAP, the correct was to do it with no worry is called ARP hardware.
Yea, i did not know i was going to be removing heads, so i was unprepared and wanted to get it together ASAP, the correct was to do it with no worry is called ARP hardware.