Inliners International
Posted By: 47Thriftmaster250 4.3 S10 5 speed... - 08/26/14 02:03 PM
I've been doing research for a while on this T5 now, and just when I think I have a plan, things take a turn. There are a couple of 5 speeds for sale near me that could work for my application... 1989 S10 w/2.8, which I could do the Jeep input shaft conversion and wa-la. But there is also a 1991 s10 w/4.3 5 spd that's for sale. Now I know that the rear of a 4.3 is the same as a small block, so one would think that the transmission would bolt right up to my 250, but I can't seem to get a comfirmed answer as to whether the 5 speed behind the 4.3 is either a T5 or an NV3500. If it's a T5, then wouldn't that be almost perfect like the hard-to-find Astro T5? Or is the tranny really an NV3500 and I should steer clear?

So, what tranny comes in an s10 with a 4.3 V6 (1988-1992)?

As always, thanks guys.
Posted By: Mitch Re: 4.3 S10 5 speed... - 08/26/14 07:25 PM
I'm almost positive it's a T5, however the best way to go about this would be to ask for the tag number on the transmission. Mine was on the tailhousing to case bolts. Run the numbers and find out!
Posted By: Lugnutz Re: 4.3 S10 5 speed... - 08/26/14 10:34 PM
Originally Posted By: 47Thriftmaster250
I've been doing research for a while on this T5 now, and just when I think I have a plan, things take a turn. There are a couple of 5 speeds for sale near me that could work for my application... 1989 S10 w/2.8, which I could do the Jeep input shaft conversion and wa-la. But there is also a 1991 s10 w/4.3 5 spd that's for sale. Now I know that the rear of a 4.3 is the same as a small block, so one would think that the transmission would bolt right up to my 250, but I can't seem to get a comfirmed answer as to whether the 5 speed behind the 4.3 is either a T5 or an NV3500. If it's a T5, then wouldn't that be almost perfect like the hard-to-find Astro T5? Or is the tranny really an NV3500 and I should steer clear?

So, what tranny comes in an s10 with a 4.3 V6 (1988-1992)?

As always, thanks guys.


I am a self proclaimed T5 addict.
I agree with Mitch, that S10 will have a T5. You will still need to modify the input shaft, even though it is from a 4.3 V6 truck. Ask the owner if the transmission has an integrated bell housing. If it does, then it's NOT a T5. All T5 transmissions bolt to the bell with 4 bolts. A T5 will never have an integrated bell housing.

Both of those T5s will be non-world class and have a pulse style speedo sender, NOT a cable connection.

Both S10 T5s would be ideal candidates for a Jeep input shaft swap.

As a general rule, the 4.3 V6 should have a OD gear of 0.72 and that is a good match for a 3.73 rear. The 4 cylinder S10s usually have a 0.86 OD gear which is a good match for a 3.42 or 3.08 rear.

My website shows how to calculate the 5th gear ratio before you buy so you know what you are getting.

I have several T5s on hand just in case you find yourself in my area, but I do ship.


Posted By: 47Thriftmaster250 Re: 4.3 S10 5 speed... - 08/27/14 02:55 PM
Thanks guys.
Posted By: 47Thriftmaster250 Re: 4.3 S10 5 speed... - 08/27/14 03:23 PM
One other thing about the 1989 2.8 V6 5 speed is that the charts show a unique set of gear ratios for it, which would work great for my 3.42's I think, at least the OD.

1st - 3.97
2nd - 2.34
3rd - 1.48
4th - 1.00
5th - 0.79
Posted By: Lugnutz Re: 4.3 S10 5 speed... - 08/27/14 04:17 PM
I agree. That 0.79 OD is perfect for a 3.42 diff.
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