2.8 to 3.4 Conversion or Swap Advice Needed - S-10 Forum
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post #1 of 5 Old 08-18-2015, 02:47 PM Thread Starter
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2.8 to 3.4 Conversion or Swap Advice Needed

Please forgive me, as I know this has been mentioned a million times already. My '88 S10 Blazer has a tired 2.8 with currently 260k on the motor. My truck has been great to me in the 10 years I've had it, and I would like to keep around for another 10 or more. I've been thinking of a 2.8 to 3.4 conversion or motor swap, based on cost, labor, modifications and vehicle down time (compared to previously thinking of braving a grueling 383 swap.) Overall, my Blazer is a family vehicle, a daily driver and really does not need much more than it already has, with the exception of a motor that can actually get off the line at a green light.

With that being said, does anyone know the difference between a conversion or a complete swap? I know a swap is pretty straight forward other than using the 2.8 as a donor for all parts needed on the 3.4 motor. But, couldn't I just bore out the 2.8 to a 3.4? Even if so, is it worth the hassle?

Also, if anyone could provide some links to conversion kits and/or crate motors with pricing and availability, it would be most appreciated. I think I'm leaning toward a crate 3.4 to eliminate the possibility of any unknown issues with a used motor, but that all depends on if it would be more cost efficient and overall worth it to just build up a used 3.4 from the block up. Thanks in advance!

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post #2 of 5 Old 08-18-2015, 08:45 PM
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Re: 2.8 to 3.4 Conversion or Swap Advice Needed

It's not recommended to bore the 2.8/3.1 block to the bore of a 3.4. The cylinder walls will become quite thin.

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post #3 of 5 Old 08-26-2015, 02:13 PM
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Re: 2.8 to 3.4 Conversion or Swap Advice Needed

Crate motors are discontinued. I bet you could still find one though if you dig hard enough. But I wouldn't bother. Just source you a used Camaro motor and build it. Prices run the gamut from used engine to crate. I mean you could pick up a block and heads for a $100 Im sure that you could build. My crate engine cost almost $2100 after freight although I don't regret it at all. Im sure there are all kinds of options in between too. Like a zoner motor. My prior 2.8 lasted 13 years and it was a zoner motor. (That's Autozone). They come in long block and that's pretty easy to swap.

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post #4 of 5 Old 09-02-2015, 05:05 AM
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Re: 2.8 to 3.4 Conversion or Swap Advice Needed

My first s10 was an 88 and I did the swap with a crate motor, pretty much plug and play. Now I have an 89 s10 that used to have a 4.3 in it and the original owner pulled it went it blew and threw in a carbd 2.8. This time I am swapping in a 3.4 from a camaro and still keeping it old school carbd. I have everything ready, just been too busy to install. Gots to get it done.
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post #5 of 5 Old 09-02-2015, 01:54 PM
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Re: 2.8 to 3.4 Conversion or Swap Advice Needed

Since you have an 88 Blazer, the swap is a lot easier. You can find a good 3.4 out of a Camaro / Firebird for under $1000 that will be almost a bolt in. Since the Camaro 3.4 and your engine both have serpentine belt accessory drives, it's a matter of unbolting your accessories (Alt, A/C, PS, pulleys) along with brackets and installing on the 3.4.
Also - the 2.8 oil pan has to be installed on the 3.4 even though they look similar. How do I know?
Motor mounts will also have to be exchanged.
The main issue: carb or injection.
Carb is easiest, but will add an extra cost to the swap. The problem with the TBI is it will run very lean and not provide full potential for the 3.4. Guys generally install a 4.3 TB and open the intake ports to 2 1/16".
If you have everything you need (which is never) you could do the whole job in a weekend.

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