i have a 2.8l v6 stock in my 86 s10 blazer 115hpi heard i can get some more power by swapping in 3.4l heads from a camaro. also a throttle body injection system from a 4.3l will add some good hp. will the heads fit in with a swapped 4.3l tbi? or will i have to modify the intake manifold? and will i also need new headers with the 3.4l heads ? or are they the same? also will the ecu need to be modified? i changed my mind about the whole japanese motor swap **** i was talking about in my previous post. im going all gm and aftermarket. seeing that my truck only weigh about 3000lbs i would be pretty fast with a modified 2.8l right? well... any other sugestions would be greatly appreciated. im looking for atleast 300 ponies if i have to bore the block its ok..ill go the xtra mile. i wanna have a one off piece under my hood. oh...im looking forward for some mufflers i want a mellow sound with a dual exhaust set up, whatbrand of muffler is recommended with mellow soundingbafflers? delta force 40? what if i use some japanese mufflers like greddy or apexi? one more thing whats the code name for my 2.8l tranny?

 

I would not waste my time on just the heads from a 3.4L. Get the whole motor. It is a direct swap in for the anemic 2.8L.

 

Yeah, it's a waste of time to swap heads on a 2.8. An entire 3.4 swap is the way to go. I did this swap a few years ago on my old 86 Blazer. Most all of the information you'll need can be found here...
http://forums.s-series.org/viewtopic.php?t=33171
Here's my old thread talking about the swap...
http://forums.s-series.org/viewtopic...&highlight=
I never had it dyno'd or took it to a track, but it did at least "feel" faster than my 96 4.3 2 door Jimmy. Granted, the 86 had 4.10's w/posiand a 5-speed,so it ran like a raped ape. If I had to guess, I would like to think it was near the 200hp mark. 200hp has been prooven on a dyno with a 3.4 swap.The only thing I didn't do to mine was bore the intake to fit the 4.3 throttle body. I used the 2.8 throttle body with 4.3 injector pods. Coulda gained a few more ponies with the bigger tb. But you're never going to see 300hp from a n/a 60* V6. Mabey if you boosted it...

Let's see, I still have some pictures from that swap somewhere....
Oh here they are...
Here's a big pile of parts ready to be installed:


Here's the old 2.8 coming out:


And here's the new 3.4 getting ready to go in: (ah memories)

 

I don't know why I have such a hard time posting pics on this site. And every time I try to edit, all the apostrophies get dooubled and tripled. WTF?

I'll try again...

 

3.4 and 86+ 2.8s use the same heads so no gains there.

To do the 4.3 TB swap you must bore the 2.8 intake out to same size as the 4.3. If using it on a 2.8 use 2.8 injectors, on a 3.4 use the 4.3 injectors.

Heads same so the s-series manifolds/headers work fine.

Your 86 uses kinda a bastard computer that was used only one year (my 87 the same way). Its still and obd1 but being the first 2 years of fuel injection we are the lucky ones, lol. A good computer reflash wouldn't hurt but really needs to be done by somebody that knows what they are doing and for the exact mods done to your motor. This means if you change anything it needs to be redone. If you were to even find one of the mass produced chips they are worthless as they leave too many variables open to be any kind of effective.

Your better off using a 3.4 over a 2.8 for any power.

300 HP is a real reach. It can and has been done but if you need that much power its would be easier and prolly better to just do a v8 swap. 60 degree motors are not really designed to put out much over 200 horses and still be reliable.

Unless you plan on having the power band in the higher RPMs a dual exhaust is not really the answer. Go with a single 2.5 inch then if you want the dual look use a dual exit muffler. This way the power band is down lower where most people have more use for it. I have a flowmaster 40 series and I like it.

In a 86 with a 2.8 you have whats called a mini 700r4 tranny. It takes all the same internal parts as the normal one with a 90 degree bellhousing bolt pattern yours just has a 60 degree bolt pattern.