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TBI to carb swap??

crzycarfreak

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Hi I just recently purchased a 87 blazer and on the way home it developed a very bad knock, it has a sbc 400 in it. So I am going to be pulling the motor soon to either rebuild it or find a 350 for it. My question is sense it has tbi(most of the plastic clips for the wiring are broke and the wiring isnt to great either) on it how and what would i have to do to get rid of the tbi and run a carb on it? i just use it to run the dogs down to the river and go play in the desert here and there.
 
alrighty then i will stick with it, im not used to the tbi on this considering the other vehicles i have owned have been older and just ran carbs
 
alrighty then i will stick with it, im not used to the tbi on this considering the other vehicles i have owned have been older and just ran carbs

X3 on keep TBI. They are really simple. Just do some research and you will figure it out really quickly. There are only like 10 sensors or so on the whole freakin thing.
 
X3 on keep TBI. They are really simple. Just do some research and you will figure it out really quickly. There are only like 10 sensors or so on the whole freakin thing.


there really that simple? good to know ill have to do some research then and figure it all out!
 
Keep the TBI, internet search for the new plug ends you need and replace them, fix any bad spots and re-loom the wiring harness. Not as bad of a project as you'd think.

I've had my complete engine compartment harness removed 3 times already, only take about 30-45 minutes really.
 
first time you go off road and tilt the truck right on a low tank of fuel and go bouncing and the carb floods out and stalls the ride you will wish you still had that dinosaur simple / stupid tbi system .

my trucks all have got the tbi swapped in and or my 2wd build got a 5.3 ls engine swap . :thumb:
 
Just to throw this out there, unless the swap was done correctly, a 400 is a bad idea with a 350TBI setup for many reasons.

Since you will be replacing the motor, if you can't be sure the PROM has been modified, and that fueling has been fixed with more fuel pressure or larger injectors (and maybe even BBC throttle body) then I'd seriously consider throwing a 350 back in it.

Without proper tuning, that 400 is and has been running lean since installed. Could very likely have contributed to what is going on. This of course will be true of any engine installed that requires more fuel and different timing than a bone-stock TBI engine.
 
Well after pulling the motor lastnight i noticed the casting on the back said 5.7 so i will just try and rebuild this one and just throw it back in, i was assuming it was a 400 just from what the previous owner told me
 
Check out Affordable Fuel Injection as well. I bought an entire stand alone TBI system to retrofit my old small block and I've been nothing but satisfied.
They make their own harnesses so I'm sure they could whip up a stock replacement for you if that's all you're after.

http://www.affordable-fuel-injection.com/
 

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