Clear My Confusion!?!? S10 Q's

[GearJammerR]

So, for starters I have a 87 S10 4x4 2.8 5 speed.

Ive owned a 91 s10 2.8 5 speed 2 wheel drive.
Between the two trucks, the 91 will blow the 87 waaaaaaaay outta the water in a race.
I can't understand why? their both 2.8 tbi trucks! I know the 4x4 is a little heavier but its not even comparable, the power difference.

Back to the point, if I retain my 2.8 short block in my truck (fresh Rebuild) could i use newer front wheel drive heads, intake and fuel injection? and still be drivable on 87 octane?

Would I be better to swap out the entire motor for a 3.4 camaro motor (hard to find for me)or could a newer 3400 fwd setup work?
Im a fairly decent Tech with lots of ressources
Thanks for the info!!!!

[95cutlassproject]

Just to throw it out there, If the truck happens to be all time 4x4 that would mean the power is being split by more tires when compared to a 2wd truck. I will let someone who is better versed in these engines answer for the cylinder head swap and the other question.

[Superdave]

What are the rear end ratios in those 2 trucks?


Yes, you can use the FWD top end on your 2.8 but with the stock pistons you'll have 12.89:1 or 11.93:1 SCR depending on what headgaskets you use. With a stock cam that's not going to work out so well with 87 octane.


You really have a ton of options, one that i'd give a good look at is to find an entire FWD 3100 (Gen 3) and swap the crank, rods and pistons into your 2.8. Then bolt on the 3100 top end with the LIM and UIM flipped. You'll need an external crankshaft trigger to run it as MPFI but they are available and if you are capable you can even make your own.

A full 3400 (or 3500) swap will work as well, chances are that the oil pan won't clear but with a sawzall you can notch the K member and then box it back in with some 1/4" plate. You'll have to use your old 2.8 timing cover and accessories and a little bit of fabrication to get everything to work just right. LIM and UIM will need to be flipped and if you want to re-use your stock exhaust manifolds they'll need to have the mounting holes opened up a little. You'll also need to find a dual starter pocket T5 bellhousing since the FWD engines have the starter on the drivers side.


If you look through my "89 camaro project" thread you may get some ideas.

Good Luck!

[GearJammerR]

Well for starters, the 2wd truck had 3.42s to 4x4 has 3.73s but a little taller tires. also the 4x4 transfercase is disengagable so no full time 4x4. also the 4x4 has a true truck trans in it so its a NV3500.

Sorry im still fairly new to the game whats does LIM and UIM mean? Also whats the my options for a external crank trigger?

[unchained01]

LIM =lower intake manifold. UIM =upper. TCE makes a 3500 external crank trigger for the 7x crank sensor. Look on his site (tcemotorsports) and wot tech. Has them on his site also. Mark and ben are so members here and are very helpful

[GearJammerR]

That sounds like a pretty big task to accomplish and nevermind the custom fab work with either choice.

How about a cam swap with the original 2.8 tbi in my truck, would that even get me any noticable gains for example: COMP Cams High Energy 16-232-4 or Same 16-233-4
Would that require any spring changes or pushrods? Would it even be worth it?? The way my truck is now, I can't even do 80mph balls to the wall so.

[Superdave]

There really isn't a whole lot you can do that will make a noticeable difference if you want to stay naturally asperated, those heads just flow very poorly. You could add a turbo or a supercharger, there is a very good deal in this thread for one: http://60degreev6.com/forum/showthre...folds-amp-carb



I'd have to do the math on it, but if you were to use a copy of a Crane H272-2 cam with the aluminum top end your dynamic compression might be low enough that 89 or so octane gas would work. You'll have to do some computer tuning no matter what though...

[GearJammerR]

Allright, the supercharger is really cool I have to admit but there is probably no way I could put my tbi set up on top of that thing and then tune it yet. Aslo it would benefit a cam swap too.

The other thing is that the idea of the bigger cam is to bleed off some of the compression? If i did the newer aluminum head swap, whats the best computer to run the set up? obd1 or obd2?

Lastly this is my DD, im not looking to have to run expensive gas all the time or be able to tie it up under construction for a long time.

**Edit** looked into Fageol Superchargers and they make one for tbi S10s but 86 only and without A/C Kinda crappy

[GearJammerR]

After doing some digging and comparing specs, I also found out that the stock cam in my 2.8 has only 0.262(int) 0.273(exh) lift. thats very brutal, Comp Sells tons with .390 and up. That must be worth some kinda extra power?

[bszopi]

My guess is that what Comp is listing is lift at the valve, not the lift of the cam. With that said, the stock intake lift would be 0.393" at the valve with 1.5 ratio rockers.

[GearJammerR]

Oh ya! that would make waaaaaay more sence! Thank you for pointing that out!!! I dont know what i was thinking.

Now im very bombarded with soo many choises, i could top end it but then i need a top end, new headers, custom pushrods, piston swapping, computer tuning ect. its not really a easy weekend job, it seems to me anyways. I could put 1.6 rockers on it but that would be minor. I could do a cam swap but that would be the same as a the rocker arms. Any other that im missing? I dont know what to to do! lol

[TechRod]

Sadly, it does seem that for a noticable improvement you'll prolly have to put the truck down for longer than a weekend.

[bob442]

what i would do, is get a 3400 block, do all the simple things to it, get it ready to swap, and use a harness from a W body 00+ to run and tune the motor. The harnesses are extremely easy to pull and wire up to get the motor running. i think you only have to hook up 6 wires and a fuel pump to make it run. if you wanted to put in a auto i think wiring it up for a 4l60e would be very easy as well, and for a stick there is a way to fool the trans to think its in drive. who ever figured it out was on Bstuff and i cant remember, someone i'm sure could help you out. or maybe even I if i looked at a wiring diagram. But definetly the way to go is getting a separate engine and harness ready to swap, ask me why....

[GearJammerR]

Thanks a bunch everyone for being very patient and helping or sugesting different ways to do everything.
I think i want to go through with just a simple plain ole cam swap. Its between the Comp 252 or 260. Id but the complete kit with springs ect. I was wondering if a computer tune is REQUIRED to have it run properly? Also whats max lift on these iron heads?

[95SleeperAcheiva]

hey, I think the 4x4 blazers came with 4.11 gears. It was a long time ago, but I swapped diffs just for the higher ratio into a 85 s-10.