Will the heads off a 1982-86 173, 2.8 GM also work on an 89 engine? Or an 87?

I just bought remanufactured heads at auction and found out they were listed for 82-86. I was wanting to put them on my 89 Firebird, but have an 87 S10 Blazer also. I really wanted them for my 89 Firebird.

Thanks,

KJay

 

yes they are interchangable, as far as i know

 

Thats good news. Thanks.

While we are on the subject, I saw some aluminum heads listed for an 89 but they seemed to have the valves sticking through the top at odd angles instead of in line side by side.

Any idea what these heads are?

KJay

 

The earlier heads will bolt right up but you might experience a loss of power. The later FI heads have the same valve size as the earlier 2.8 HO heads. So unless your heads are from an earlier HO engine, your valve size will be smaller

 

In response to the second question... the other heads are from a 1987 or later Generation II V6. They incorporated a splayed valve geometry (similar to a big block Chevy) and were used in FWD cars from 1987-on. These will not work on a camaro as the pistons would need to be changed and the ports for the intake manifold would not match up

 

Let's get back to simple.
The heads from a 1985 & ABOVE MPFI (the F BODIES, ONLY!!) at the hot ticket.
Heads from S-10 Blazers & such are not desirable.
They are for torque, not HI FLOW
The SPLAYED VALVE ALUMINUM HEADS ARE FRONT WHEEL DRIVE ONLY!!!
For your real education, please go spend the measly $6 at the ANY GM DEALER and get the GM PErformance Parts Book. ALL those answers are shown with pics & such.
Real GREAT simple investment.
Wil they fit, sure. are tehy the right solution?
Get the GM book and find the correct answer and then know why, too.
PS 3.4 heads from F BODY are the BEST! Read book to find out why!

 

Thanks, I'll get the book.

Thats why I came here. To find out what I dont know.

 

Promise
REALLY WORTH THE EFFORT!!

It does help so much!!
I reread your first item.
IF you want primo heads, you own them now!
BUT, you must FULLY rebuild them (guides/new springs) to get max value of what ya own.
NOW if YOU WANT TO PORT & POLISH, you certainly may spend $$.
Expecting return on investment?
YOU MUST SHOP FOR MACHINIST PRICES to help guide you.
New 3.4 heads go for about $600 pair.
I paid $800 for my running 3.4 w/40K miles.
Do YOUR math to help YOUR mission.
Plan.

 

Well, he could measure the valves on the heads he bought. That'd tell us if they're the 82-84 heads or the 85-up "high output" fuel injection heads.

 

These are the heads I bought. http://cgi.ebay.com/ebaymotors/aw-cg...149752&r=0&t=0

I thought I could save time and money by having the heads ready when I disassembled the engine.

I e-mailed my questions to the seller but he did not respond until the auction was over. I decided to take a chance anyway and won the bid.

These were his late comments:

THESE HEADS ARE FOR A 1982-86 173, 2.8 GM

YOU NEED TO CHECK YOUR CASTING NUMBERS. IF YOUR
CASTING NUMBERS END WITH 877, 292, 258, OR 882
AND ARE CAST IRON HEADS THESE WILL WORK.

I'll measure the valves when I recieve them.

Thanks for your help guys. I really appreciate it.

KJay

 

I belive Fiero heads are a direct bolt on and Fiero's had the high output version of the 2.8. I am pretty sure they had better heads, cam, and possibly intake. Hope this helps someone.

 

The factory cam of the MPFI 2.8 & 3.1 is IDENTICAL.
The 3.4 is the aggressive cam.
The intake and such from a Fiero are OK.
Heads?
NOT SURE, but if you have the 85 & above 2.8/3.1, you have the same heads.
3.4 heads are the same, but different.
Get the GM Performance parts book and see the difference.
Measly $6 from any GM dealer!
Fiero Valve covers are the hot ticket, cause they look nice.

 

those gen II heads were for the most part used up until '93, though some were used later. by '94 most FWD switched from MPFI to SFI.

that's why my '94 grand prix has a 3100 SFI than a 3.1 MPFI.. the genIII heads offered a 20 hp/5 tq increase over genII. Imagine what gen III heads would do on our genI headed motors. if only they'd work.. we'd roughly be @ 170hp

I'm thinking this because the gen I headed fwd 2.8 gen I heads 120 hp pre 86 (82-86?)
RWD 2.8 gen I heads carbed 120 hp 82-85
fwd 2.8 gen II heads 130 hp 87-90
RWD 2.8 gen I heads 135 hp 85-89
fwd 3.1 gen II heads 140 hp 89-93
RWD 3.1 gen I heads 140 hp 90-92
fwd 3.1 gen III heads 160 hp 94+
RWD 3.4 ????????????? 160 hp 93-95
fwd 3.4 gen III heads 180 hp 97+

this is for non OHC and NA motors, so I won't count the 3.4/3400 DOHC 205/215 HP screamer, or the 89-90 3.1 TGP 205 hp.

RWD motors got shafted. they are @ the gen I head "level" imagine if GM had given us progressive improvements, other than barely negligible internal "improvements."

I gotta stop hanging around Clup GP and the v6 board here.... I know too much piddly things about the 60* motors.

 

keep in mind that the fieros motors were transversely mounted..... they had a transaxle. like a FWD car, but flipped. their are some differences, but still off the shelf parts. Like GM would have made ONE car line model have totally specific motor parts. it's gotta be a multicar line. i.e.
f-body
w-body
j-body

well.... except the vette.