What to do?

[Mike7ftr]

New member. Thanks for all the good info.
I recently purchased a '87 3+3 4x4. It came with a 454. I'm swapping it out for the 6.2. I found a '82 Blazer which is a red block. Right? It is being sold with a Banks Sidewinder kit. However, it's all 1/2ton.
Then I found a '91 3500 4x4. I think it has the serpentine belt already. I'd get the complete drivetrain. Which would you say would be better, and why?

 

[74 Shortbed]

Welcome to the site.

 

[1987 GMC Jimmy]

Okay, so yours is an R3500? The '91 model has a 454, too, yes? So I'm also guessing your '87 has a TH400 in it, and the '91 has a 4L80E? Sorry, just trying to clarify. The 6.2 is a great motor. It's reliable, offers great potential longevity, and it's easy to troubleshoot and repair. While the turbo kit will wake it up some, it is an underpowered motor, and I don't think it'd treat an R3500 good (just assuming these are all RWD trucks). Now if you're looking at a 454/4L80E combo in the 1991 truck, and you can get the drivetrain and wiring harness, that sounds a lot better. If you don't mind my asking, why are you swapping out the 454 already in there?

 

[Honky Kong jr]

Welcome. Me I'd stick with the 454 gasser. Or if I'd go diesel I'd go Cummins but that's me.

 

[yevgenievich]

I would vote 91 3500. 4x4. already has 4l80e(or should) with controller and 241 transfer case with vss signal.

 

[Mike7ftr]

The '91 is a 6.2l. They are all 4x4. I'd like better mpg's and in the future go to the 5.9 Cummings. I live in Ca so I must go to 6.2 first in order to get the change recognized by the DMV. So says the smog referee. He's the boss. The 454 in the truck is tired as well as a gas guzzler.

 

[Honky Kong jr]

The '91 is a 6.2l. They are all 4x4. I'd like better mpg's and in the future go to the 5.9 Cummings. I live in Ca so I must go to 6.2 first in order to get the change recognized by the DMV. So says the smog referee. He's the boss. The 454 in the truck is tired as well as a gas guzzler.

Gotchya.....

 

[1987 GMC Jimmy]

Okay, so is yours a 2500 or 3500? In this case, I'd go with the later serpentine 6.2 and build it up a little.

http://www.trucktrend.com/how-to/engine/0554dp-62l-buildup/

 

[Mike7ftr]

Mine is the R30 1ton. I was leaning towards the '91 as well. I had the truck trend article bookmarked already. That thing looks nice. Nice and pricey.
Thanks for the responses!

 

[rt66paul]

I remember reading that hooking up the Cummins to the 4l80e means problems with the electrical to the trans, but I think there is a fix, but it is always expensive.

 

[1987 GMC Jimmy]

I wouldn't use a 4L80E with the Cummins. A 47RH would be a lot more sensible because it can handle the torque/HP output.