4.3L HP upgrades

[Schurkey]

You're putting a diamond in a goat's butt. The ONLY reason to hop up a 4.3 is if you can't fit a 350 in its place... ...If someone tries to gift you a 305, kick 'em in the junk... ... tune that turd up!... ...Upgrading the exhaust is one area where you can upgrade a 4.3

Quoted for truth. Well-said.

I especially like the part about the goat's butt. Yup, we're talking about a 4.3L.

If we were talking about an Iron Duke, it's be the pimple on the goat's butt.

 

[618 Syndicate]

Anything can be made fast, it just takes money. That said, what you start with dictates what your budget will get you.
As stated repeatedly above, if you're looking for power it's easier and cheaper to upgrade to a V8 than turbo or supercharge a 4.3, unless you have the stuff sitting around, know how to fab and tune, and just want to be different.
Last 4.3 I owned was in a 2wd xcsb NBS. Great truck, hauled what I needed it to, got decent fuel mileage, dead reliable. Just not fast. Sold it to my neighbor a few years back, he daily drives it.
These peeps are guiding you in the right direction, follow their guidance.

 

[Schurkey]

Anything can be made fast, it just takes money... ... it's easier and cheaper to upgrade to a V8 than turbo or supercharge a 4.3

You've reminded me that GM did a pretty fabulous job with the Typhoon and Syclone...but not everyone has GM's resources; and neither vehicle was inexpensive.

They were, however, V-6s with hairdryers, and had plenty of power.

 

[618 Syndicate]

You've reminded me that GM did a pretty fabulous job with the Typhoon and Syclone...but not everyone has GM's resources; and neither vehicle was inexpensive.

They were, however, V-6s with hairdryers, and had plenty of power.

They dropped that motor in a T/A GTA as well, they're like hen's teeth now.

 

[L31MaxExpress]

Even a 305 will run circles around a 4.3 of the same generation. After having built several of them for chump change, they are not the evil people make them out to be. 10 years ago I bought one with 60K well maintained miles for $250 from the throttle body to the pan, put a ZZ4 cam in it using comp 787 retainers and LS6 springs, bolted headers on it and put it in a 1997 AWD Astro van with a magnaflow Y-pipe for a 96 C1500 and a 3" catback exhaust with a magnaflow muffler. I had less than 2K in the whole van and with the cammed 305, headers, exhaust, factory high stall converter and 3.73s in both ends it would really get up and go and got really good fuel mileage. At that time a used 350 Vortec with 2x the miles would have cost me atleast $1,000. My 99 Tahoe also got a 305 Vortec that I did rings, bearings and a cam in.

I personally would save money toward a v8 swap and only add things that will carry over. Tuned 0411 swap, larger radiator with dual electric fans, 3" catback exhaust, and maybe some march underdrive pulleys. I bet a Volant CAI would fit the 6 too, never tried it but the TB is in almost the same location as a V8. Don't waste money on V6 specific parts like a cam or headers.

 

[Erik the Awful]

At that time a used 350 Vortec with 2x the miles would have cost me atleast $1,000.

...but would you take a 305 now if you could get a 350 for under $100?

 

[L31MaxExpress]

...but would you take a 305 now if you could get a 350 for under $100?

I would if I could get one with really low miles compared to a worn out 350.

 

[LC2NLS6]

Ok, so clone the SyTy setup. Headers, downpipe, fab up something to attach to factory exhaust maybe. Now, slap a chinese turbo on it, ok, oops, need a wastegate, weld that on the up-pipe preturbo, now cold side, fab some tub from pieces from Spectre and a chinese intercooler. Now, fuel, time for a big fuel pump or dual intank setup, well, hotwire it so another big relay and wire. Injectors? Boost referenced fuel pressure regulator? There are some AN fittings that are $30-45 each out there. Lord help ya if you can fab a fuel system without ever buying extra fittings, I know I never can. $1500 fuel system for what ends up being $1000 in what is actually used to plumb it, toss the $500 spare ones in for next project bin. Ok what injectors? How control the ECU tune? 3 bar map sensor. Oh, and then find out the GM knockoff plastic 3 bar's all leak air and are useless so end upgrading to a metal chinese one. Easily a $7-10K turbo conversion I'd bet when all said and done. Even if get a blow through carb, those aren't cheap and have to adapt the manifold to take a carb and figure out timing when under boost.

 

[JCribb]

Back to the tune up side, I have a 98 4.3 5 speed ECSB 4x4. I took it in on trade, and it ran like dog shxx.
I learned a long time ago that for some reason these vortec motors run best with AC Delco plugs, and I pulled out the champion plugs that were in it.
I like rock auto for parts or eBay, because they’re almost always cheaper than anywhere else.
Case in point, the AC plugs at my local parts store were almost $9 a piece, but rock auto had them on sale for $5.50 each. I also had a code for an upstream o2 sensor, so local price was $50 each, rock auto was $20. These were for the same exact part numbers I’m referencing. So for $50 I had a whole tune up for what would’ve cost me $154 local.
Shop around and compare parts numbers and different websites for the best deals for everything, that’s my best advice for you young man. I’m 41 and wished I had heard anything similar coming in the car scene, now I don’t know if I would have listened to much of it, but it would have been nice to hear.

 

[Glynn]

E Fan will get you the most butt dyno feeling.