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looking to build a 4.3

1K views 11 replies 7 participants last post by  Haggar 
#1 ·
would like any input on building a 4.3 for my 98 blazer, going to go 30 over for sure and probably a cam and stuff, just not sure how far i wanna go, will have around 1500.00 for parts and machine work, labor will be free. This is going to be my daily driver so dont want to go too crazy. any suggestions would be apprieciated! Also would not be against buying a motor that has already been built. Thanks
 
#3 ·
For $1500 I would slap a turbo on it and call it a day! I was looking at 4.3 mods and that is the cheapest dollar per HP mod you can make. 4.3's have very strong bottom ends already so really you don't have to mess with any internals as long as you don't go to crazy with the boost. I seen a 4.3 liter in a Bravada take a Vette 0 to 100 :sonicjay: I am not sure but I think the Cyclons and typhoons used 4.3 liters instead of the 3.8? If so there is parts already available for this mod, I just figured the wifes Bravada did not need that much balls and decided against the turbo. Instead I am going to do a few simple mods like 1.6 rockers, a better flowing exhaust a tune and a few tranny mods.
 
#5 ·
don't waste your money because you will be disappointed with results. the biggest problem with the vortec 4.3 engines is the injection system. not very programmable and doesn't respond that well to changes. unless the engine is worn don't bother boring it .030 over because you won't gain any measurable power from it. and unless you swap it to a TBI setup or go carbed installing a bigger cam will make it run like shit. i have seen people install bigger cams into Vortec trucks and get worse MPG and power because the computer cannot handle the changes.
 
#10 ·
yes you can. take the engine, wiring harness and computer and anything else attached from a 96-99 half ton. make sure you get it from a 4x4 automatic so that all wiring will be identical to the blazer and should be a simple swap.
 
#12 ·
If you do want to read up a bit on what you can do, search, I believe hot rod built up a 300 4.3 (although, thats probably 250 SAE hp...). The write up is on their site somewhere.

They aren't really all that buildable. If you know someone who can do TBI tunes, it'd probably be the way to go, use vortec heads and a 4 barrel manifold, with a tbi adapter, if you want to keep injection.
 
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