S-10 Forum banner
1 - 11 of 11 Posts

·
Registered
1989 gmc s15 sierra 2.8 manual
Joined
·
43 Posts
Discussion Starter · #1 ·
So I'm starting to make my list of parts and stuff to do to my 1989 218,xxx miles 2.8 tbi Vin R. Since an engine swap isn't going to happen in the near future , although it might happen but hot in the 2-3 years to come. I want to make as much as possible out of this engine without going all-in with my credit card. My goal here is to make decent to decent+ daily/weekend power gain , get a good sound out of this engine(I have heard some 2.8 v6 sound like a v8) , and make the engine bay a bit prettier. The list I started is:
1.headers
2.cams
3.intake upgrade
4.tbi rebuilt
5.nice chrome valve cover&air filter housing
6.e-fan upgrade

Now for the queations:
1.i start reading all over this forum about headers for these 2.8. All I have managed to gain is that the only one who makes headers for 2.8 is headman headers. Are they any good ? How hard are they to fit and what else should I bare in mind regarding to headers?
2. Again from what I have read over here , comp cams 260 is the best way to go , since I do not have allot of knowledge about cams upgrades , and although I have messed with allot of OHV engines , but never with a pushrod engine , what should I look after when getting a cam upgrade ? How hard is it to disassemble/reassemble the camshaft without pulling the engine from the truck ? Does the heads must go off (only thing I think about is the pushrods falling into the camshaft housing in the engine block) , what else should I put on the bucket list if I opt for a cam upgrade.
3.i know there is no of the shelf intake upgrade for 2.8 tbi engines, and the only thing there is to do is to bore the stock intake , since it seems to me as a pretty hard task to tackle by my self , how bad would it be leaving the intake as it is? Is there any other option out there ?
 

·
B4U Task Force Admin
Joined
·
30,357 Posts
3.i know there is no of the shelf intake upgrade for 2.8 tbi engines, and the only thing there is to do is to bore the stock intake , since it seems to me as a pretty hard task to tackle by my self , how bad would it be leaving the intake as it is? Is there any other option out there ?
There are aftermarket intakes out there..might be difficult to find. @Mad Max can help you out with upgrade info.
 

·
Boozebag
Joined
·
9,969 Posts
Again HotP, thanks for the tag.

Hmmm, credit card abuse?

There are quite a few mods you can do to the 2.8 that are fairly easy.
First, what are your parameters? Stay with TBI or run a carb?
It is easier to run a carb since TBI would require boring the intake to accommodate a larger TB, and then "tuning" the ECU. The TBI intake is not a great piece for performance.

For a cam: Edelbrock makes a Performer Plus cam which is almost a copy of the GM crate 3.4 160HP cam.
Crane also makes roller rockers for the engine.

Probably best if you read this:

2.8 and 60* V6 Performance Mods

If you have any questions, I can fill in the blanks.
 

·
Registered
1989 gmc s15 sierra 2.8 manual
Joined
·
43 Posts
Discussion Starter · #4 ·
Again HotP, thanks for the tag.

Hmmm, credit card abuse?

There are quite a few mods you can do to the 2.8 that are fairly easy.
First, what are your parameters? Stay with TBI or run a carb?
It is easier to run a carb since TBI would require boring the intake to accommodate a larger TB, and then "tuning" the ECU. The TBI intake is not a great piece for performance.

For a cam: Edelbrock makes a Performer Plus cam which is almost a copy of the GM crate 3.4 160HP cam.
Crane also makes roller rockers for the engine.

Probably best if you read this:

2.8 and 60* V6 Performance Mods

If you have any questions, I can fill in the blanks.
Thanks for your input I've gone through your threads a couple of times.

I intend to stay with the tbi because I want the simplicity and the reliability of the tbi. But I maybe be able to get the intake bored and upgrade to a 4.3 tbi injectors , I can resource most of the stuff in my country (bare in mind I'm relying on ebay , rockauto , summit/jegs+international shipping..). About ECM tune , I have read that the 2.8 ecm can handle a 4.3 injectors on a 2.8 TB assembly with a bored intake

About the cams , I admit I'm not that knowledgeable about cam specs but sure can swap one myself , what would be my choice if I'm not looking to gain Max spec from it , I'll be happy just to make it breathe better maybe even gain a 20-25hp and some tourqe.
What's my best choice for cams for this application ? And do I must replace to roller rockers?

How about ignition ? Is there any aftermarket ignition system to these engines ? or just go through a good tune-up with factory?

What about the rest of the exhaust after the headers? any good aftermarket recommended exhaust system to install after the headers ? Currently I'm with the original system+a crappy cat and it will be much more cheaper to built a exhaust from parts online Then going to a local fabricator. What are my options for that ?
 

·
Awww..you ain't got shit!
Joined
·
3,613 Posts
My truck is an 84 with a crate 3.4 and it has been retrofitted with a TBI system from a 2.8 truck. I had a machine shop bore out the intake. I took them a gasket so they had something to go by. Cost about $60. Well worth it.

Stock ignition is fine. I don't see any real credible gains from swapping it over on a daily. Looks cool, but I don't think it really does much.

Now as far as the exhaust, I run some older Edelbrock headers that aren't available anymore. They run into a Y pipe like factory, then to a Dynomax cat, and then to a 40 series Flowmaster and dual out the back. Professionally done and it's a work of art under the truck. Dude...it sounds INCREDIBLE. I mean really aggressive, but not just loud or splatty. It does drone a little, but not bad considering. Now, I will say that the converter I put on it also improved the sound because I had it in the past with just a flowmaster muffler on it, and it didn't sound like this. Not bad, but the converter made a lot of difference. Plus it really needs to be on there and it's significantly cheaper than a new stock style one. I'm much happier with it than if I cobbled it together. Cost me $500 out the door.
 

·
Awww..you ain't got shit!
Joined
·
3,613 Posts
But I will mention that you will need to tune the truck after modifying the intake. I've never done it, but I can tell you it would benefit from it because it requires 93 octane fuel or it pings like crazy and causes other driveability issues.
 

·
Boozebag
Joined
·
9,969 Posts
Thanks for adding JimmyK
What country are you in Sieera?
There are a lot of variables involved. Cams make a pretty good difference with TBI tuning.
If you have access to tuning shops, then cool. If not, I am going to recommend the Holley 4 barrel way since it requires the minimum skrewing with performance gains. Bolt on and go.
There are a lot of different problems to overcome once you are in a foreign country. Mainly shipping, and tuning shops
 

·
B4U Task Force Admin
Joined
·
30,357 Posts
Thanks for adding JimmyK
What country are you in Sieera?
There are a lot of variables involved. Cams make a pretty good difference with TBI tuning.
If you have access to tuning shops, then cool. If not, I am going to recommend the Holley 4 barrel way since it requires the minimum skrewing with performance gains. Bolt on and go.
There are a lot of different problems to overcome once you are in a foreign country. Mainly shipping, and tuning shops
Israel.
 

·
Registered
1989 gmc s15 sierra 2.8 manual
Joined
·
43 Posts
Discussion Starter · #9 · (Edited)
i really appriciate everyones input guys!
Thanks for adding JimmyK
What country are you in Sieera?
There are a lot of variables involved. Cams make a pretty good difference with TBI tuning.
If you have access to tuning shops, then cool. If not, I am going to recommend the Holley 4 barrel way since it requires the minimum skrewing with performance gains. Bolt on and go.
There are a lot of different problems to overcome once you are in a foreign country. Mainly shipping, and tuning shops
as Rhotpursuit said. I'm from Israel. 1st gen S10/S15/sonoma got pretty rare over here in the past 10-15 years, and 2.8 even more {i think i can count on one hand the amount of 2.8 in runing condition all over the country...}. so for replacement parts im good but for performance parts, especially for a 60*v6 eBay/amazon/jegs/summit/rockauto etc are my only way to go {good luck to me..}. so i really need to plan my startegy before clicking add to cart like a child in a candy store.{and the reason why I'm asking so many questions over here :LOL:}. for the dilema rather staying TBI or going carb well..i belive if i look good enough around here i could find a nice carb to install but im very skeptic {i know for sure i can find a stock 2.8 carb but they are trash}. i could defenitly find tbi units for 4.3/5.7 much much more easily. nevertheless does sound like a cool project to swap a carb to my truck {BTW i have very few to none expiriance around carburetors. i know the principle but never actually got to mess with a carb..}.so just to make things more clear so i can make a price estimate and shopping list. if i go carb ill need:
1. a good carb{such as a Holley 390/Edelbrock of some sort}wich will cost around 300-600$+shipping.
2. intake manifold{since the stock one is super restrictive}.around 300+shipping at edelbrock
3. headers.600$+shipping
4. camshaft+new rockers.about 200$+shipping
5.a new exhaust system{since cat converters are mandatory from 1994 and up i can forget about the cat}
6.swap to a mechanical distributor
7.throw all unnecesery wire harness+ECU {such as ECT to the ecu , TPS , IAC , EGR ,etc}
8.run a mechanical fuel pump{or could i just use my tank fuel pump and wire it so it gets +12V ACC?}
just from this generic list im at around 2300-2500$ include shipping {wich is an optimistic estimate..and didnt even include small stuff such as water pump gaskets valve cover etc}

now if i choose to run TBI. seems to me like im going to end with a much less wounded wallet. just all the above minus the carb , distributor, intake, and ECU delete... now I have a place that can bore my intake to accommodate 4.3 fuel spitters, now i doubt if there is a credible tuner around here that will know how to mess with an OBD1 ECU and tune it correctly, so could i just run an EPROM out of a 4.3 TBI or maybe swap a 4.3 ECU into my truck?

bare in mind that this engine is 32 years old with 350K km on the clock... who knows how much life it still has{even though it still runs like a champ doesn't smoke or burn oil/coolant👊👊}, so i really need to think if all this investment can be carried over when this engine will give its last breath {probably ill swap a 3.4 when this will happend}

P.S Sorry for such a long reply, I'm literally the first person in my country to even think of tuning a 2.8 V6.

But I will mention that you will need to tune the truck after modifying the intake. I've never done it, but I can tell you it would benefit from it because it requires 93 octane fuel or it pings like crazy and causes other driveability issues.
well the minimum octane over here is 95 unleaded so i dont have a worry for engine detonating.

my main goals are to get a HP/TOURQE bump without tearing the whole truck appart aka engine swap or complete engine teardown
stay on as low of a budget as possible
.this truck is daily driven/weakend cruiser so not looking for an asphalt shredding drag strip killer, just a cool daily driver/weekend cruiser. and to do somthing special and diffrent since there are really few to non 60*v6 over here not even a single one that has been tuned or modified.. i dont know if this guy is on this forum but i bumped into his youtube account and he really got me all over to do this project.
 

·
Boozebag
Joined
·
9,969 Posts
Well... I've offered to help various members on the forum, no one has taken me up on the offer.
I can help you out.
I've seen used Edelbrock intakes on eBay for $125 to $200
A used Holley 390 for about $150 - sticker shock!! Way more $$ A Weber 38/38 with adapter will work too.
Headers are about $250 new.
You can buy an exhaust system from Summit Racing for about $175
Timing chain - $75
Gaskets - $75
Cam/lifters - $175
Miscellaneous - $150

Your worst enemy... Shipping.

I know many eBay participants won't ship overseas. I can do that for you. I have friends in Saipan who I send parts to, so it's not really different.
BTW, is this an automatic or 5 speed?

Timing chain: Sealed Power KT3-373S Engine Timing Gear Chain Set 81-95 GM 2.8L 3.1L 3.4L V6 | eBay

WOW! Used Edelbrock intake: Edelbrock 3785 & 3789 Performer 4BBL Intake Manifold for Chevy 60* 2.8 or 3.1 V6 | eBay

Weber carb - will need an adapter. A Holley 390 is super expensive - Carburetor For Weber 38 2 Barrel Fiat Renault Ford VW Dodge Toyota Pickup Jeep | eBay

Cam kit: CHEVROLET Edelbrock 3790 Edelbrock Performer-Plus Cam and Lifter Kits | Summit Racing

Headers - these are what I have - Hedman Hedders 69376 Hedman Street Headers | Summit Racing

Just a guide for pricing.
 

·
Awww..you ain't got shit!
Joined
·
3,613 Posts
Boy I gotta say that inflation seems to be out of control right now. I couldn't believe how expensive that 4bbl has become. I paid about $400 for the one I had on my truck and now it's like $650 at Summit! I found another shop selling one for $587, but that is still out of control.

Max is right though. Bolt on and go with the carb and intake. Just depends really on what you want to do. I don't have any real regrets about the swap on my truck though either. Both are very good options. I had the 4bbl and Eddy combo on my truck for years. 5 years on the old 2.8 and 3 on the 3.4. Performance is similar, but the EFI does provide more power.
 
1 - 11 of 11 Posts
Top