Softailguy

Hello all. Im new here so please forgive me if this has been covered before. I have a 99 blazer ls with the 4.3 4x4. Friend of mine is selling his 04 silverado 1500 4x4 with a 5.3 to me dirt cheap bc its got frame rot. The drivelines fine but the trucks not worth saving to him. Anyway, ive been watching videos on youtube about swapping engines. I know i have to mod the crossmember, get electric fans etc. My big question is this. My blazers throttle is cable driven. His is drive by wire. Is it a simple fix like putting the throttle position sensor on the gas pedal when i switch the wiring? Or do i need to get a different intake manifold and keep it cable driven?

bandit_601948

I have a 99 blazer 4.3 too ! a 4.3 is nothing but a 350 with 2 cylinders missing ! everything off the Silverado should fit on your blazer ! all you have to do is switch everything over from the truck to your blazer !

Softailguy

Thanks for the input. Im aware that the 4.3 is just a 5.3 or 5.7 with 2 cylinders chopped off. Its the different intake setup thats throwing me for a loop. From what i can see ill have to add the throttle position sensor from the silverado as well. Probably not the hardest thing seeing as im getting the whole truck as a donor to work with and i have access to a whole shop full of fabrication equipment.

SBchevyfan

Can you just swap the intake manifold from your 4.3 onto the new engine? If so, everything should work as it did on the stock engine?

Softailguy

I honestly dont know. I imagine itd be too short, and short 2 intake ports. Itd also be most likely more work than adding the tps. Guess im lucky that i have literally an entire donor truck to monkey with.

SBchevyfan

Misread your post, thought you were swapping a 4.3 for another 4.3. Are they both TBI engines?

Softailguy

Yes, theyre both tbi, my 99 is cable driven while the 04 is computer actuated. Theres a sensor on the gas pedal telling the computer how much to open the butterfly

SBchevyfan

You might want to see if your old throttle body and cable can be mounted on the new manifold. If so, I would think it would be a fairly straight forward swap.