I have a 1989 IROC with the stock L-98 but its got some miles on it and needs a rebuild. It runs great but smokes a little at start up, valve seals I'm sure. Anyway I ran across a 1988 L-98 corvette 350, complete with all accessories, computer and everything for a deal. It only has 42,000 miles and runs great. What exactly are the differences other than the aluminum heads? I am thinking about buying it and installing a TPIS mini ram intake and an LT4 hot cam. Basically to have a dependable driver that I can drive across the country with no issues. Has anyone had experience with these TPI motors? Are they comparable in HP or about the same?

Thanks

 

nothing,

 

Sounds like a good deal.....but....I'm not sure I'd put that cam and intake on it. Heads will hold you back. ....with such a good running low mile engine, (assuming it really is) your best bet is to leave it alone. Not saying I'd prefer bone stock, but you negate the value of a low mile untouched engine by tearing into it.

 

Aluminum heads are the only difference. Power is 5hp difference I think.

I agree with Abubaca. Put it in and enjoy it stock. Thats your best bet for dependable driving.

 

They have abit more compression and were supposively rated 5-10hp more than fbody's of the same year. I think they do abit better than fbody's personally from what I've seen. There are many many bolt on L98 vettes running 12's compared to fbodys. They dont weight much different either

LT4 hotcam works well in those setups as long as the heads are modded to handle the valve lift with the cam.

 

Corvette weighs a little less. Something like 200 lbs less than the Fbody car. That is why it is faster really.

 

Look up the weights, its not 200 lbs less. Most vettes are in the 3300-3400 range just like an fbody.

EDIT: and I mean street trim with their larger wheels. most are advertised at 3250 or so but most i've seen weighed come in the mid 3300 range. I know my L98 fbody was 3400lbs. Vettes may be a tad lighter but not 200 lbs unless you compare a heavy optioned fbody that can reach 3600 like a GTA or something.

 

You're kidding ...Right!

Nothing fits but the long block and then you still have to drill and tap a hole in the right head for the acc. brkts.

Fuel rail, pan and wiring, all different.

 

vette heads have 58cc chambers and screw in studs while iron l98 heads have 64cc chambers and press in studs... fuel lines routings are different.... vettes have egr tube that goes in the head, different dizzy, vettes use the old style intake pattern... there is actually alot of LITTLE differences but power wise its about the same....

my dad and i both have the cars in comparsion your talking about.my dad has a 91 vette l98 all stock.. honestly its not much faster if any than my GTA back when my l98 was all stock... he has a zf 6 speed along 3.55 gears which makes it feel faster.... i wouldnt swap my heads out for his l98 heads because its not worth it unless you port them.. i know for a fact my car weighs 3420 pounds without me in it right now.. my dads vette should be no more than 150 pounds max lighter than mine..

 

Could I use my stock L-98 fuel rail and pan? So the right side head has a different pattern for the accessories? That doesn't seem too hard to remedy. I agree with you guys though, since its a low mile good running engine I'm just going install some headers and my new magnaflow and run it that way. Hard to pass up a low mile corvette L-98 though

 

Yes, and you have to use the 'vette intake (different bolt pattern) your runners and plenum, distributor, etc.

 

Awesome! Too easy, thanks for the help!

 

You can just elongate the center 4 bolt holes like the aftermarket intakes do to suit both bolt angles

Need F-Body oil pickup on pump.
Vette pickup one wont fit F-Body pan

 

Or You can get an 85-86 TPI manifold. It has the same bolt pattern as the vette. An or get an aftermarket manifold.

 

I got 88 113 heads for my 87 IROC what whole for assessories I have v belt and I elonged the holes and a full port and polish

 

To further clarify the EGR difference, The corvette heads dont's have the egr passages. Because of this, there's an egr pipe that runs from the exhaust manifold to an opening on the intake.

Vette 113 heads have 3 accessory holes on one side (the side thats front on the driver head) and only two on the other (the side thats front on the passenger head). The missing hole is the one closest to the block.

 

 

 

You can also see the vette EGR tube running over the valve cover on the pass rear of the this motor.

 

Looks like my 88 but in better shape.

 

The extra bolt hole on the head helps but isn't required. The Acc bracket will be supported just fine using both block holes and the one head bolt hole.

 

My 113 heads have 3 bolt holes on both sides what does that mean I have to left heads or smething else

 

Where did your heads come from?
The ZZ4 heads ( over the counter Hp version of L98 113 heads ) appear to have all three holes drilled / threaded

 

Used they have 3 on front and back on both 113 casting brown springs

 

There is still a hole that needs to be drilled/taped on the pass side for the use of Fcar serp brackets. I'll have to take a pic of it. I do them all the time..

 

So what do I have a modded pair 113

 

pull a valve cover and let us know,should see some numbers inside the heads

 

They are of and have 113 casting # on both

 

they are prob ported too,dont u also have a mild cam?

 

The same '113 casting was used for both L98 Vette and ZZ4 heads;
which came on the ZZ4 engine or could be bought over the counter as bare castings or complete

 

They are not ported rough like my stock heads

 

my zz3 is basicly the same as a vette l98
if you have serpentine the lack of the bolt hole in the head dosnt matter much i just didnt put the bolt in no vibrations even when running the ac

you can drill out the 4 center bolts on the intake to make the fbody intake work

thats the only differances i noticed when installing in my car

 

Old but my 3 holes

 

you there i was hoping to know if the expertec books 4 tpi were good