4.3, 5-Speed swap

[oldmansmonte]

The S10 used a T5 trans built by Borg-Warner, now owned by Tremec. 4.3L Chevy is a 350 with #3 and #4 cylinders lopped off (3.8L/229 Chevy was a 305 with 3/4 missing). Serpentine accessories and bellhousing/flywheel interchange between 4.3 and the 305/350.
3.8L Buick uses an entirely different bellhousing and the flywheels are going to be pretty rare - not sure if a '70s Buick 350 flywheel might work. Some early 70's Jeeps used the 3.8.
The easy(er)-to-find G-body '606' bellhousings only fit a 12.5" 153-tooth flywheel that takes a 10.5" clutch disc. This is what was used in the 80s Camaros.
The S10 T5 almost exclusively came with a 4.03 first gear/0.86 overdrive. The F-bodies had better choices - 2.95 or 3.35. Only the '93 S10 models were 'World Class'- set up with the better bearings to handle more torque. But, GM for an unexplainable reason, used a Ford bolt pattern on the front of the trans - if you go this way, you must use the S-10 4.3L bellhousing it came with - hydraulic clutch system.
The 4.3 L motor does not have a lot lot of performance parts available. You could try to use the factory TBI system, or locate a small 4-BBl carb for it. I think Edelbrock may have made a carb intake for it.
If you want fuel economy and a manual trans, find a running 3.8L Camaro or Firebird, 1993-1996 and take EVERYTHING fan belt to yoke. This T5 had a 3.35 first gear like many of the Mustangs. The shifter from an F-body comes up in a good place in the floor on a G-body, right about where the floor shift comes up out of the console.

Sorry for the stream of conscious. The range of options is pretty wide and generally good only if you have just the right luck.

The 3.8 was a unique v6 engine design and was not a 305 with 2 cylinders cut off.

 

[oldmansmonte]

Hi,

I am your resident 4.3 and TBI expert(If I can be called that). There are only 2 4.3's you'd have the opportunity to do this with. The original 4.3 with TBI and the later 4300 Vortec. The first generation 4.3 TBI was not a huge HP maker. Started at 140hp and later upgraded to 160hp. This would have been avail from 88-91(in other vehicles like Monte carlo's, Caprice's and Astro's from 1985 on). If you go with this generation motor you will want 3:73 gears to make this worthwhile. Otherwise it will be slow and boring and not worth your work. Also its an unbalanced motor so it tends to feel like its running rough no matter what you do.

The other option would be the 4300 Vortec. This motor was significantly stronger motor (195hp-260 ft.-Lbs) and you could feel it in the gas pedal. The motor had balance shafts, roller cam, modified heads, port injection and other modern goodies. This one will be much tough to install due to the differences in the wiring harness/ECU and such. I believe those blazers/S-10's had an electronically controlled transmission so that could be an issue as well. I heard there may also be some difficulty hooking up with the older 90 degree bell housings due to changes in the motor.

Personally, If your looking to do a project like this I wouldn't limit the search to the 4.3. Do a 305 or 350 if you're lucking enough to find one cheap. The 4.3 just isn't that special of a motor.

 

[oldmansmonte]

If your starting with a motor that had the TBI heads your at a loss to start with. With intake ramps being the biggest problem. Those head keel over at around 4200rpm. Get a good set of vortecs bolt them on and a upgrade cam and your easily their. All motors are just air pumps. The more in the more you get out. Those early TBI heads were good for just going from point A to point B with good low end power.

The heads won't fit. You cant do I top end swap on the 2 different generation motors. I looked into it.

 

[clean8485]

GM actually produced 2 different 90 degree 3.8LT V6 engines that were available during the same time period. There was the 3.8LT, 229 cubic inch Chev V6, VIN code K, which was basically a 305 with 2 less cylinders, and is in the same engine family as the Chev 4.3LT V6, and the 3.8LT V6 231 cubic inch Buick V6, VIN code A, which eventually became the 3800 V6, which was a GM corporate mainstay up until recently.

 

[pencero]

I'm not a mathematics guy so I was exaggerating about the 250 hp but tbh hp #'s not even something I looked at when I had the Blazer but I was looking at the torque numbers and they went up after the chip removing the rev limits / top speed/ and changed the shift points to match my rear gear (I think it was a 3.42 but its been a long time) hp was about the same consistently but I definitely gained torque w/ the air intake and chip. I took on my friends 96 blazer that he wasted money on his vortec and even though I had the leather seats package I smashed him in a race. Then I smashed his cousin's newer v6 mustang in a race so badly he put it up for sale immediately. Not friends w/ either of these guys anymore. If you set up the 4.3 right you will have a line of haters whose excuses for wanting to fight you are utter fassads and they really just hate how fast your sh*t is lol. I doubt I ever made even 220 hp but I'm 100% confident I made nearly 300 torque w/ the 2nd blazer which had the 4L60E instead of the older 700r4 in the 1st one I had (which was significantly slower than the 1 w vortec heads on it)

 

[oldmansmonte]

I'd have to go carbureted because I don't mess with computers, call me lazy for not wanting to learn, but I'm not going to touch a car's computer, ever.

There's a guy near me who is a 4.3 freak. He's like an '88 S10 4.3. He painted it baby blue and has the 4.3 with a Holley 460cfm(I think) Carb, custom made tube headers and flowmasters with an H-pipe. Pretty mint. He told me to close my eyes and tell me it wasn't a small block firing up. It sounds amazing. Goes pretty good too. Its too bad you don't live closer. I have the 52,000 mile 4.3 out of my car just sitting in storage. Ran great and burned minimal oil. I also have a holley TBI I didn't use from my project. I would have given you a smokin deal.

 

[pencero]

I was really interested in the 4.3 until I considered how obvious it would sound like a Blazer firing up to everyone and it wouldn't seem like an oldsmobile anymore. The 3.8 has a very pronounced 'I am definitely an oldsmobile or buick' sounding exhaust note but the 4.3 sounds so obviously chevrolet and you can hear it coming from a block away even w/ single exhaust let alone duals lol. When I had the Blazer people always knew it was me and I didnt even have to call them on the phone to tell them I was outside when I was picking them up they were already coming to the door.

 

[oldmansmonte]

I was really interested in the 4.3 until I considered how obvious it would sound like a Blazer firing up to everyone and it wouldn't seem like an oldsmobile anymore. The 3.8 has a very pronounced 'I am definitely an oldsmobile or buick' sounding exhaust note but the 4.3 sounds so obviously chevrolet and you can hear it coming from a block away even w/ single exhaust let alone duals lol. When I had the Blazer people always knew it was me and I didnt even have to call them on the phone to tell them I was outside when I was picking them up they were already coming to the door.

This is true

 

[pencero]

http://southbend.craigslist.org/cto/4712692883.html Ran into this CL by coincidence. If any1 near me was looking at the 4.3 w a 5 speed here it is and thats the 2wd so the trans should work . Sure wont help the OP all the way out there in vegas tho lol

 

[RustRocket]

Thanks everyone for the input, I'm trying to ask as many questions and gather as much information as possible in case I ever decide to build up a G-Body, the current car probably wont stick around for more than a couple years, but it's great to have the future knowledge