JuttyShabango

Bought a 91 GMC Jimmy last night 4x4 for 400 bucks. Runs and drives fine.

Gonna pull the motor 4.3 liter-non vortec-TBI No extra crap! Looks like the motor swap in the Trekker will happen now sooner than thought. Plan to have the motor rebuilt and all that, then stick it in with the AA bellhousing adapter for the yota trans.

I'm stoked. My motor (22R) is tired and needs to be replaced. This will make an excellent donor vehicle.

Gonna part the rest of it out. Just keeping the motor and computer.

seaflea

Great find!
How soon is the conversion taking place? I'm assuming after Tellico?
Doesnt that also have 63" rear springs? they would also make a great swap

JuttyShabango

Definately after Tellico. Figure it will take a week or 2 to rebuild the motor, have the heads ported and polished, all that.

Painless makes a wiring kit that will terminate everything properly so that's a HUGE step out of the way. Ordering the Adapter today.

I want this thing in and tested before I leave for Colorado July 1st. That's the goal.

seaflea

Wow! youre not leaving much time to sleep.
That is a lot of work, Painless makes a great kit. if I ever do something like that I will use them instead of trying to do it myself. You, know you are going to be obligated to do the write up and post pics daily so we can watch the process.

4Hummer

NICE Score.

YEs you will have to post allot of pics of the build up.

Have fun and keep us updated

BOSTON4RUNNER

as a 4.3 is simply a small block chevy V8 but two cylinders smaller alot of the same applies

if I were you I would definitely swap in a nice torquey cam, upgrade the valve springs and definitely toss in the flat top pistons...which will have 4 eyebrow reliefs...the factory pistons in that motor will have 4 eyebrow reliefs but the pistons will be dished

I would pay special attention in porting to the valve bowls as this is where the most restriction is

new valves are like 6 bucks each, I would definitely get a set of 2:02's and 1:60 exhaust valves...probably worth an honest 20hp on the top end

the flat top pistons will be worth 2-3hp per cylinder,,,so probably pick up 18hp there by putting in flat tops and bumping the compression to 9.5 or 10 to one...

with the port work and a decent cam, will be super driveable, have tons of power and not ping, and not be bad on gas

I would also find a 4 barrel intake, they sell them new for that and run like a 550 to 600cfm edelbrock carb..I run holleys forever and love them, but now runn barry grants...it is true that sometimes offroading holley carbs will have some problems in the floats due to steep inclines or declines that you may have your truck on while offroad

if you do these few upgrades, you will not be sorry, and will only be a few bucks more to do this

if that doesnt work, let me know and I will rent you the engine from my camaro...I would also suggest an MSD 6AL..so you have a rev limiter, also will offer more power and a little better mileage

JuttyShabango

It's definately going to be a chore. Fortunately I have a couple pro-mechanic buddies going to do all the hardwork

I'll do a write up and play-by-play for the site. No doubt. The EFI is the one thing that has me stoked. Cold weather starting will be nice this coming Winter.

The added torque and HP will also be nice

BOSTON4RUNNER

this is from Edelbrocks site, this is what I would run

if you can score a pair of Vortec heads they flow better and they also make this same intake to work with Vortec heads....again even if you could score the Vortec heads I would recommend the valve size increase

Performer 90° V6 (Idle-5500 RPM)

Designed for street 1985-95 200-229-262 c.i.d. (3.8 and 4.3L) Chevy V6s. Will not accept stock automotive carbs or 262 T.B.I. unit. Dual bolt pattern waterneck fits both automotive and marine applications. Produced 18 more horsepower than an older manifold design on 4.3L marine engine. See Power Package Graph.

Performer 90° V6 (non-EGR) ....#2111*

jimbo74

i think www.engnbldr.com even has stuff for the cheby

BOSTON4RUNNER

oh,,,,keeping the injection

well scratch the intake idea

however, I would recommend Edelbrocks EFI intake...which they make for the V6 4.3

here is a description and part number of that intake..

Chevrolet 90° V6
Performer 4.3L T.B.I. V6 (Idle To 5500 RPM)
Designed for street 1987-94 Chevrolet 4.3L V6 with factory Throttle Body Injection. The Performer 4.3L intake manifold provides outstanding throttle response and torque increases from idle to 5500 rpm. #3713 is a stock replacement/street legal part for 4.3L T.B.I. V6; 1987-94. A computer chip is available at no charge and is street legal for 4.3L trucks (E.O. #D-215-21). Return the postage paid card that comes with the manifold to receive the chip. Manifold and chip provides a 6/10s of a second gain from 10-70 mph. Accepts all factory accessories/hardware. Throttle body unit remains in stock location. Not for vehicles with flash memory computer. These are most 1994 and later 4.3L T.B.I. V6 equipped vehicles. Flash memory ECM is located underhood. Will not fit 1986-89 Astro/Safari Vans. See Power Package Graph.

Performer 4.3L T.B.I. V6 (EGR) ....#3713

JuttyShabango

WOW!!!! That's great info and thank you for taking the time to post that up!!

I will head your advice. I've heard from some threads on Pirate guys are turning their floats down on the carbs and having great luck with them on inclines. What kind of gains or top ends do you think I can get following your advice?

Motor looks awesome btw...what a beauty.

BOSTON4RUNNER

I would honestly say

using the EFI with an Edelbrock intake
ported heads with 202 and 160 valves
MSD or other aftermarket ignition
flat top pistons
good engine rebuild

I would say no problem at all making 260-270hp out of that motor which measure 262 cubic inch, should easily make 1hp per cubic inch without being some radical undriveable beast....will run great go anywhere and have tons of power

another good thing about an MSD, is that you can get an adjustable timing computer from MSD that wires right up with the MSD...it allows you to make timing adjustments right from the drivers seat..this will help you obtain better mileage on the highway (by turning timing down) it will also help you say in super super hot weather, crank the timing down for easier starting etc

you can find an MSD 6AL on ebay as well as a timing computer...

I have bought MSD 6AL's for 40 bucks at swap meets and in the Want Ad..timing computers have also paid like 40 bucks for

even if you score a bad MSD box..you send it to MSD and they rebuild it for like 50 bucks.....(they rarely fail though) they are totally sealed and even the circuit panels are coated so they can be totally soaked with water and still run

buying all the stuff new, intake, cam, valves, valve springs, msd, msd timing computer you would probably be at a grand...however i bet you can find the MSD stuff used

building the V6 with machine work, all these parts and paying someone to assemble etc I would think 2 grand should be all together... Northern Auto Parts which is a mail order out of like Washington State or something has rebuild parts cheap...as will Summit

go talk to a local and good machine shop..they might also get a good deal on the parts and would be one stop shopping, make sure it is a shop that likes and is experienced doing performance work and will be eager to swap in flat tops etc

last thing you need is some bozo telling you to leave it stock and steer you away from horsepower and torque

and on the other hand you dont need to get all scientific either, a basic port and polish...matching the head ports to intake gasket and some valve bowl work will make a big difference...usually Fel Pro makes larger gasket sizes..call Fel Pro, talk to their tech and ask them what they recommend for a gasket from them that will be good for gasket matching/port job

tell them your goals, will will then say I think you should port match it to our our part number such and such...then you will be on your way

also thanks for the compliment, just finished the stereo in the camaro and am moving on the the e brake cables, then final body work preparing for paint

JuttyShabango

Thanks again for the tips. I will definately heed your advice and will more than likely poke ya' for a couple questions when it gets started. Man, you know a ton about this and thank you!!!

Great info.

BOSTON4RUNNER

yeah i know a decent amount about chevy stuff and performance overall, worked at a race shop all through college, grandfather had a body shop for over 50 years, my dad is in the business etc

even with that, i didnt know what 'discos' were until the other day..

so we all learn something new as we chug along in life

JuttyShabango

Yeah, I'd say you know your stuff for sure. Man, thanks again for some great info.

I'm digging around for the adapter plate and Downey has them but says I need the 84-Newer 5 Speed Trans and I have the 82 SR5.

I don't mind switching transmissions, my concern is the Crawl Box mating up to the newer one..might have to call Marlin and ask them.

Does anyone know the differences between the years? I was under the impression that all 4cyl 5 speed trans were the same. Not so?

seaflea

Not so, you probably have the g-52 tranny while the w-56 series started out in 85 I think. You can go on Marlins site and check there. Thats where I gained my minimal knowledge.

JuttyShabango

My head is spinning after reading all that...Okay, it looks as if the Crawlbox will work just fine with the g-52 but need to get a G-52 now. Then the Downey BellHousing kit will work. Need to think this thru so I'm not doing installs 2wice. Wondering now if I should wait 3 weeks and not do the crawlbox till I start the motorswap. I'm pulling the motor this week and dropping it off at my buddies shop to start rebuilding it asap.

Might have to turn on the jets for this project and GetRDone like by the end of May. Once I get goin' it will go really fast.

seaflea

Ha-ha. Now tha youre head is spinning, go back and look at the gear options in the G-52 and the W-56. the g-52 has a lower 1st and 2nd gear. sounds like a better choice, BUT since you are going with a v-6 you amy want to look into the r-150 tranny from the 3.0 v-6 models. they have a 23 spline output and are heav duty compared to the g-52 unit.

JuttyShabango

Update on this:

After losing my job earlier in the week, I put a few extra toys up for sale and ended up working a trade with some buddies of mine near my old shop. I donated my tubing bender and trailer to the shop and in return, I'm getting this motor swap done for me! Parts, labor etc. I already have the bellhousing adapter kit from Downey (motormounts and adapter) so this should be a piece of cake for me at least.

What a relief. I'm going to keep updating this thread weekly, target install is by the end of this month. The guys are pulling the motor out of the Jimmy today.

seaflea

Its all about the karma!