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Discussion Starter #1
One of my friends is converting his 84 Blazer 2.8L 5-speed over to 4.3L Vortec injection. Thing is, can his stock T-5 hold up to a 4.3L Vortec?
 

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well how does the kid drive it?? becuase you have to becareful if the blazer came with the 5speed from the 2.8L it might not be a T5, they also came with izuzu units, but even of it is a T5 its alot weaker then a one form a v8, but if he drives it like a normal person then it shouldnt be a problem, your best bet is to tell him that whne he breakes it ( will probaly split the case doing it lol) just to get a GM tremec T5 or the borg warner T5 from a v8 car the bellhousings should be the same
 

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i saw what you did there!
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sic ones said:
One of my friends is converting his 84 Blazer 2.8L 5-speed over to 4.3L Vortec injection. Thing is, can his stock T-5 hold up to a 4.3L Vortec?

i see factopry 4.,3L t-5 s-10s and they hold up fine, so i dont see why it cant hold up, unless you rail the piss out of the truck and tear it up, just like you can with any other drivetrain and blow it up,.
getting too good of rear tire bite adn launching the truck from dead stops like a moron will amost certainly bust tranny or driveline or axle eventually, no matter what drivetrain you have


if you drive normally and responsibly then youll be plenty fine

good luck
 

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Discussion Starter #4 (Edited)
Sorry I was so vague. My friend just wants to tow his axled smoker, 4-wheeler trailer, and stuff like that with it. Of course, he also wants to be able to tow a friend home(namely me!) in the case that they mess something up on their car or what ever. Oh yeah, and hes got 31x10.50 A/T's on there right now, and the tranny is definitely a T-5.
 

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Discussion Starter #6
IOWABOB said:
The 2.8 trans wont bolt up to the 4.3 block--- the bolt pattern is different.
Well, he was kinda figuring on using the full-size truck bellhousing as described in the JTR V8 Conversion Manual.
 

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IOWABOB said:
The 2.8 trans wont bolt up to the 4.3 block--- the bolt pattern is different.
not only that, but the flywheel is different as is the clutch and the input shaft. advanced adapters makes a custom clutch to use the 2.8 tranny against a 4.3/v8. But talk about EXPENSIVE, now your adding in 31's, I dont think that 2.8 tranny will live long. They had t5's in fullsize trucks????? Never heard of that. That had t5's in v8 camaros and fireturds.
 

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Discussion Starter #8
rivbluenoma- Well, the JTR Book refers to a "bellhousing from a 1988-1992 full-size truck (GM# 15562385, $160)." They also say you can use the stock S-10 clutch, but you have to cut a little bit off of the clutch otherwise the splines will bottom out on the input shaft. Im sure you could probably use a 4.3L manual tranny flywheel.
 

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Ive got a 91 sonoma that was originally a 2.5/t5 set up. I did the 4.3 swap into that truck. The 2.5 and 2.8 share the exact same tranny, clutch and so on. I went out and bought an 92 v8 camaro bellhousing and it bolted up just fine. But the flywheeel that bolts up to a 4.3 or small block are much larger than what a 2.8/2.5 use. The clutch from your 2.8 truck will not make contact with the flat area of the 4.3 flywheel. Its like trying to match a dime(your 2.8 clutch plate) up to a quarter (4.3 or v8 flywheel)
You cant just put a 4.3 or v8 clutch on the input shaft spline of your 2.8 T5 because that trans uses something like a 1" 8 tooth spline (approximate sizes), while the 4.3 and v8 t5 uses something like a 1 3/8" 18 tooth spline. Advanced adapters makes a bigger clutch with the smaller spline set up specifically for what you are doing. But I think the clutch/pressure plate assembly cost around $400 thru summit racing. That kind of money could get you a 4.3 tranny and save you a lot of headaches. Took me 9 months to do my swap because of all the headaches and BS and the fact that there wasnt really anyone I could ask because people as a whole dont know shit about this stuff. I didnt know about the forums at the time. Instead spent months beating my head against the wall. All Im doing is trying to save you guys that frustration.
 

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Discussion Starter #10
rivbluenoma said:
Ive got a 91 sonoma that was originally a 2.5/t5 set up. I did the 4.3 swap into that truck. The 2.5 and 2.8 share the exact same tranny, clutch and so on. I went out and bought an 92 v8 camaro bellhousing and it bolted up just fine. But the flywheeel that bolts up to a 4.3 or small block are much larger than what a 2.8/2.5 use. The clutch from your 2.8 truck will not make contact with the flat area of the 4.3 flywheel. Its like trying to match a dime(your 2.8 clutch plate) up to a quarter (4.3 or v8 flywheel)
You cant just put a 4.3 or v8 clutch on the input shaft spline of your 2.8 T5 because that trans uses something like a 1" 8 tooth spline (approximate sizes), while the 4.3 and v8 t5 uses something like a 1 3/8" 18 tooth spline. Advanced adapters makes a bigger clutch with the smaller spline set up specifically for what you are doing. But I think the clutch/pressure plate assembly cost around $400 thru summit racing. That kind of money could get you a 4.3 tranny and save you a lot of headaches. Took me 9 months to do my swap because of all the headaches and BS and the fact that there wasnt really anyone I could ask because people as a whole dont know shit about this stuff. I didnt know about the forums at the time. Instead spent months beating my head against the wall. All Im doing is trying to save you guys that frustration.
So what did you do? Are you running a T-5 or what?

Without me knowing, my friend just picked up a Camaro bellhousing. I think its a Camaro bellhousing because the slave cylinder is on the driver side... We managed to get it bolted up to an old T-4 I had in my back yard, so we atleast know it fits.
 

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The 1985 or so Chevy Astro vans used the small input (1" diam. x 14 spline) T5 trannie behind the 4.3L 90 degree V6 engine. That is the same size input shaft as the T5 behind the small V6 and I4 engines. The Astro 4.3 V6 used a 11" clutch disc in the 1 x 14 spline input. IMHO, easist way to get everything together would be to score an Astro bell housing, pressure plate, clutch disc, and (if needed) flywheel.

The Camaro bell housings all tip the trans toward the driver, which just doesn't go with what you need for an S-10.

Piper106
 

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yeah, i forgot all about that 15 degree slant in the camaros bellhousing. Had no clue about the astro van set up, hell i never knew they had 4.3/5spd in an astro of all things. Sic ones: I finally got fed up and had a 700r4 built, too bad that tranny shop didnt do a good job and now its junk. Im working on a NV1500 from a 96 4.3 s10 at the moment. Should know how well that worked out in a week or two.
 
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