[BuDDaH]

I have a '85 Chevy S-10 Blazer 4X4 with a 2.8L and a 5 speed tranny. I would like to keep the 5 Speed and replace the 2.8L with a 4.3L, but can it be done? I have read from other places that I would need to go to a auto trans and I really don't want to. And what else would I need to change? <img src="confused.gif" border="0">

[ November 14, 2002: Message edited by: BuDDaH ]</p>

[Wmarden]

I don't know if the 5 speeds are the same, but I do know that the lower end chevy fullsize trucks for years had a 4.3 backed by a 5 speed. I would venture a guess that they may be the same transmission. If that is true it would be a fairly easy swap(if there is such a thing).

I assume you have the s-10 blazer. You can even put a 350 in those with a little work, so the 4.3 should be doable.

[roys63]

The 2.8 is a 90 degeree v6 the 4.3 is the same as the V8s the bolt pattern is different , you have to change the trany to.

[Ohio-Dan]

You can bolt a 4.3 to a 2.8 trans. The 85' S-10 used a T-5. The trans to bell bolt pattern is the same as other GM sticks. A bell from an 80's full size will work. A 4.3 has the same bell pattern as a 305 or 350. Get one with the slave cylinder. Your 85' should have a hydrolic clutch. The pilot part of the input shaft will need cut to make it shorter. Take about half of what is there off. Use a clutch disc from a 5-speed Astro van. It is an 11" disc with a 1"-14 spline hub. You can use a standard 1 piece seal flywheel and 11" pressure plate. You will need a 4.3 S-10 4X4 oil pan and pickup tube to clear the front diff. You need to change the motor mounts. I don't remember if the frame on an 85' has the holes for the mounts or not. There is a bunch there. You might luck out. The radiator has the inlet/outlet fittings on the wrong side. You'll need a 4.3 radiator. None of the brackets off the 2.8 will work either. The S-10 never has a 4.3 with a carb. Your 85' doesn't have anything to run injection. What way you go with that is up to you. When the General put the 4.3 in the S-10 they upgraded alot. They used a NV3500 instead of the T-5. That T-5 is not the same as the one used in Camaros. It's alot weaker. The transfer case was upped to a NV231C from the NV207C you have now. The olny differences between the two was a 1/4" wider chain in the 231, improved oiling in the 231, and they did away with the straight cut gears in low range the makes all the noise in you 207. The 207 is plenty strong to handle a 4.3. Your rear axle is a 7.5" 10 bolt with 26 spline axles. The 4.3's used 28 spline axles. In first gear, low range you will have enough torque to twist an axle. That is if you have enough traction to stop the wheel from spinning. All in all....a bunch of work. As a mater of fact.... The same as if you where going to put a V-8 in. If you do decide on a V-8, find a NV3500 trans to start with. By far a better gear box. Dan

[roys63]

OK i am wrong i thought the bellhousing was part of the trany in these years, Have i been working on to many Fords?

[roys63]

OK i am wrong i thought the bellhousing was part of the trany in these years, Have i been working on to many Fords?

[Ohio-Dan]

Naw, working on Fords won't hurt ya. The 1 peice bell/trans you are thinking about is the 4.3 trans. Its a NV3500. The 2.2 4 cyl uses a NV1500 that is the same way. Some of the early 2 wheel drive trucks had a 1 piece deal as well. Don't know for sure what it was exactly. Most had a T-4 4-speed or T-5 5-speed with a removable bell. I have never seen anything other than a T-4, T-5, or NV3500 in a 4X4. Dan