Quadrajet 4.3 build suggestions?

my 85 Chevy 4.3l v6 came with a computer controlled carb. so the seller tossed in a normal quadrajet
now I finally got to looking at the normal carb and it appears to be 850 cfm :?

now for the engine I plan to run a 262 cam, hei ignition.
possibly vortech heads, if I can fab a manifold.
the bottom end will be stock with GM or better bearings, with stronger rings,
11" clutch and flywheel, a t-90, overdrive, 5.38s and 32" diameter tires.

I want to have a solid power plant to tow an m416 down the road and into the woods on the local wheeling trails, hopefully avoid the water, (i'm never going into the deep end of the pool again :evil
and I also have a snowplow for this, so a good idle and low end control is preferred which is the reason for the large clutch.


aside from the T-90 does this look to be an acceptable plan? my known concerns are:
is the carb is too big, and is the cam to much to plow with at 1300-2000 rpm?

I know this is the best group to ask! hellokitty

 

The Q-jet will only deliver what the engine needs, so it will not be dumping a wad of gas...unless the engine can take it. They are commonly known as hillbilly fuel injection.

BTW if you are putting a carburated 4.3 together, have I got a prize for you! PM sent.

 

Thanks.

as far as a carb rebuild kit, I'm using a normal carb from a v8 on the v6
so do I use the kit for the carb although it is from a v8?
I'm lost because the 4.3 carb had electronics...

 

I also have a 1985 4.3 with a factory 4bbl, but it was a non computer carburetor with no wiring present to indicate it was changed out (and it appeared to be completely factory). It was in a C-10 pickup w/ standard trans, so might try looking up that combination, all the computer on it controlled was the distributor with a knock sensor. Very simple setup, saved the whole harness from the truck to go with the engine for a future project. Not at home at present or I would get the number off the body of the Q-Jet for you.

 

Check the distributor as well. Very good possibility it was computer controlled. If so it will need swapped as there is. I provision for ignition advance. DO NOT use one from a 229 Chev as they are semi oddfire and will NOT work correctly with the 4,3/262
You will most likely need to re-jet the Q Jet for your V-6 or will run too rich in the idle mixture circuit.


Sent from my iPhone using Tapatalk

 

thanks nickmil for making me verify (I neglected)
I thought I had 2 262ci 4.3l distributors here and the one 200/229ci when...

I have one even fire 7pin HEI for the 4.3, with vac and mechanical advance (from another member) with 6 evenly spaced tabs on the reluctor wheel and stator

the 4.3 i bought had a distributor in new condition that is actually not even fire ... with 3 evenly spaced tabs on the reluctor wheel and 6 uneven spaced tabs on the stator
this explains the seller wanting to get rid of the engine so affordable after never being able to get it running right. but it also means one bank was always way off in timing.

I'll have to clean and tear the 4.3 apart to look at the bores for damage asap.
both distributors have vac pots, 45 weights, but the springs are different. so I think i'll put the 4 pin module in the even fire distributor, or put the even shaft assembly and stator in the 4pin case that is in very good condition.

then there is the distributor on the 200... which is very tired and abused

 

hopping to tear into the engines in the coming weeks, I'm trying to determine any major advantages between the even fire 4.3 crank vs the semi odd fire 3.3 crank.
both even and semi odd cams are available in what i want
I have both HEI dizzys, and it will be forever carbed

from what i've read the biggest advantage for the semi odd fire goes to the 3.3 crank having sbc spec rod journals
if i want to go with a performance rebuild i could use true 350 pistons and rods, allowing the use of a partial 350 build.
It would be similar to a 383 in parts changing, aside from the 3.3 distributor and cam.
there is also a noticeable..
bop bop,
bop bop, when putting down the trail that is just unique; not even, not odd, something between that makes you want to have a heart attack

and in the other corner is the stock 4.3 which also has a 2pc rear seal, has weaker true even fire rod journals, I guess this would be the route to go for just a rering should i find minimal wear once i open the can o' beans

 

Unless supercharging, nitrous oxide, or turbocharging the evenfire crank is plenty strong. The Racejeep 4.3 I built is evenfire and has 13 1/2-1 compression with a .621 lift cam with solid roller lifters, true roller rockers, and Brodix heads with 2.08 intake valves. If an evenfire crank can live behind that and the abuse I put it through racing I doubt you will have an issue in a mildly modified engine if properly built.


Sent from my iPhone using Tapatalk

 

that looks like a mean motor, stock rods? what lobe separation? and what redline are you comfortable with?
my jeep being mostly street driven, a mild cam, and the gears should hold the revs fairly high on the interstate (2500),
more bearing area will help keep rod journal wear down right?
a healthy semiodd 4.3 would also be a unique sound. the 3.3 stock would mess with the Harley riders.
so if they are evenly strong, I would enjoy the bop bop of the 3.3 more at 13mpg if it is not a weakness.
I was also thinking of 4.3 tubular manifolds and vortec heads down the road.