Lt1 Heads On A L98!

[87L98Z52]

I am doing the research now for the switch of a tpi intake to a lt1 intake.i went on the site where the guy sells lt1 intakes that are adapted to fit l98's.i see how he has to change the bolt holes to match the l98 heads and was wondering if i can skip this step by just changing over to lt1 heads.i wanted to do a head change anyway as a part of my cam,head,intake,exhaust setup.is this changeover possible?what would it take to do?
My original plans called for the zz9 cam,ported 113 or afr heads,miniram intake,hooker headers.BUT,since i have to limit my budget,i am now looking into the lt1 intake conversion to save $.i have a friend with a lt1 that is converting to the lt4 setup and would give me his heads and intake.so i figured that if i can somehow bolt the lt1 heads ,after a little porting,i can knock out the heads,intake part in 1 step saving lots$.he already has his intake and heads off so they are ready to send out for the poting,intake adapting if i want them.

 

[Mad-Mic]

I am doing the research now for the switch of a tpi intake to a lt1 intake.i went on the site where the guy sells lt1 intakes that are adapted to fit l98's.i see how he has to change the bolt holes to match the l98 heads and was wondering if i can skip this step by just changing over to lt1 heads.i wanted to do a head change anyway as a part of my cam,head,intake,exhaust setup.is this changeover possible?what would it take to do?
My original plans called for the zz9 cam,ported 113 or afr heads,miniram intake,hooker headers.BUT,since i have to limit my budget,i am now looking into the lt1 intake conversion to save $.i have a friend with a lt1 that is converting to the lt4 setup and would give me his heads and intake.so i figured that if i can somehow bolt the lt1 heads ,after a little porting,i can knock out the heads,intake part in 1 step saving lots$.he already has his intake and heads off so they are ready to send out for the poting,intake adapting if i want them.

save yourself the money and time. if he's going to give it to you then see if the owner of www.lt1intake.com will do the labor on the conversion. LT1 intakes and heads don't match up with the SBC1 waterjackets. it has been done but i don't think the time and money would be worth it. sell the LT1 heads cheap and get some money back for the intake work.

best of luck!

 

[87L98Z52]

Thanks for the fast reply mad mic,if i can just you 1 more ?
How much would my stock heads hold me back if i just opt for the lt1 conversion and zz9 cam for now?i dont have headers either but i do have the front and rear y pipe and flowmasters now.i figured i can just do the heads and headers at a later time when i can spend that much on making my joyrides more joyfull!LOL
THANKS!

 

[bossvette]

the LT-1 is a reverse cool motor (the water cools the heads first then the block) and the water passages are different then the L-98, even though they may bolt on I don't think they will work very well.

 

[vader86]

LT1 heads are setup for the reverse cooling, so those wont work.

The 128 heads that come stock in 87 are said to be good for about 300-325hp untouched.

Ported, you should be able to get 350 to 375 out of them before air flow becomes a problem at high rpm.

They would not hold you back with a ZZ9 cam if they were ported, unported they shouldnt actually kill off major HP but you wont be at the full potential of the cam, which i think is in between 300 and 350.

 

[Mad-Mic]

Thanks for the fast reply mad mic,if i can just you 1 more ?
How much would my stock heads hold me back if i just opt for the lt1 conversion and zz9 cam for now?i dont have headers either but i do have the front and rear y pipe and flowmasters now.i figured i can just do the heads and headers at a later time when i can spend that much on making my joyrides more joyfull!LOL
THANKS!

87 heads won't flow the rate needed for the lift of the cam. i think the cut off is .480" lift. the guide plates have to be cut down so you'd have to machine the heads anyway. find a good machine shop to do it and they should work with you about how much you want to spend on the machining for extra power ect. thats the boat i'm in now. i got the LT1 intake, ZZ409 cam, and a few other goodies ready to be put on. just need a set of heads. i also am building a shortblock so i'm in no hurry for the heads at this moment. just trying to see how quick i can get her with out touching internal's right now. i think i'm just gonna buy a set of Dport 113 heads and have them reworked so the cam can clear the lift on 1.6 RR's which will be .555" lift.

 

[Mad-Mic]

LT1 heads are setup for the reverse cooling, so those wont work.

The 128 heads that come stock in 87 are said to be good for about 300-325hp untouched.

Ported, you should be able to get 350 to 375 out of them before air flow becomes a problem at high rpm.

They would not hold you back with a ZZ9 cam if they were ported, unported they shouldnt actually kill off major HP but you wont be at the full potential of the cam, which i think is in between 300 and 350.

i think i'm in that 300-325 hp at the crank now. so far so good when i redyno the car next month after a few more bolt on's (AIR elim kit, crank pulley, MAT relocation kit) i'll let you guys know what she pulled.

last time i dynoed i was hot when we hooked her up as i just got there and on my first pull blew a home made rubber EGR tube from the header install i did (rushed it to the dyno before shaking down everything ) and i thought it was a header gasket cause it was around 7:30 at night but she pulled 240 rwhp and 345 rwtq. i'm sure cooled down and now she'll pull in the 270 rwhp range and about 370 rwtq. with the other mods i will install (AIR elim kit, crank pulley, MAT relocation kit) maybe in the 290 rwhp 380+ rwtq range. atleast this is what i hope. we shall see then i am going to swap to the LT1 intake and see what the difference is on the dyno since i get dyno time so cheap from www.HeffnersPerformance.com at 80 bucks an hour

i'll let you guys know the how it turns out

 

[87L98Z52]

From talking to tpis,my understanding was that i would just have to change springs,lifters,rocker arms to install the zz9 in my 128's.with the stock springs,etc it only takes up to .480 lift.i didnt think there was any work needed to the heads to install the new springs.am i wrong?

 

[Mad-Mic]

i was told (not by TPiS) that the cam would not work cause of the guide plates needing cut down. yes you are corret about the .480" lift but the exhaust side is .520" lift.

ZZ-9 HydraulicRoller:

Intake Exhaust Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112

mine is

ZZ-409 Hyd Roller:

Adv. duration 287/287, duration @.050 226/226, Lift .520/.520. 112 LSA.

granted these specs are on 1.5" RR's i'm going to use 1.6" to get the .555" lift might want to ask TPiS about the guideplates needing cut down for the lift to clear.

better to be safe than sorry

 

[87L98Z52]

Sorry about that mic,what i meant to say is that the stock heads with stock springs only take up to .480 lift.i did know about the .520 on the exh side.i am going to contact tpis though because i have there insider hints book here and ill tell you what it says.

"one prob to beware of with chevy aluminum heads with cams over .480 lift-if the valve springs are shimmed this can be a prob.our zz9 cam does not need to have more than 95 psi on the seat,which should give you enough retainer to guide clearance."

I am going to ask them though because i also have there01' catalog and they have yourzz-409 cam listed as dur 225,240 lift.525,.558 with 116 lobe sep.
they have the super profile l98 listed with the spec you gave for the cam you have.must be some kind of mix up!

 

[Mad-Mic]

Sorry about that mic,what i meant to say is that the stock heads with stock springs only take up to .480 lift.i did know about the .520 on the exh side.i am going to contact tpis though because i have there insider hints book here and ill tell you what it says.

"one prob to beware of with chevy aluminum heads with cams over .480 lift-if the valve springs are shimmed this can be a prob.our zz9 cam does not need to have more than 95 psi on the seat,which should give you enough retainer to guide clearance."

I am going to ask them though because i also have there01' catalog and they have yourzz-409 cam listed as dur 225,240 lift.525,.558 with 116 lobe sep.
they have the super profile l98 listed with the spec you gave for the cam you have.must be some kind of mix up!

-=Jeff=- sent me the cam w/ cam card i'll have to look at it later when i get some time and let ya know the exact specs from cam doctor

 

[87L98Z52]

THANKS,it does sound like a nice cam!i will let you know what tpis says about all this when i talk to them.do you have any idea what kind of idle the zz9 or your zz409 have.i am looking for something with a little bit of a lopy idle.

 

[87L98Z52]

i have been looking into the lt1 heads on a l98 somemore and have found out there are people already doing this.lt1intake.com has 2 links on his website that tells you how.by doing this conversion,the lt1 intake would now be a bolt on plus you would still have to drill the hole for the dist.but you would have good flowing heads and a nice intake for alot less than afr heads and miniram.the only other issue im now looking into is how the acc would bolt on to the lt1 heads.look into these articles off of johns site,does not seem to be to hard of a conversion.they plug the large coolant ports and just drill a small hole for the stock coolant hole by using a head gasket from a l98 head.the exhaust ports are the same as the l98 ones also.

 

[87L98Z52]

Found a thread on this also

http://www.thirdgen.org/techbb2/showthread.php?s=&threadid=178262

seems very possible!again,my only concern is the alt,etc bolting up.does anybody know if they have the same mounting holes as l98 heads?

 

[-=Jeff=-]

Mad- mic right with cam specs

here they are off TPiS's website

ZZ-9 HydraulicRoller:
Intake Exhaust Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112

ZZ-409 Hyd Roller:
Adv. duration 287/287, duration @.050 226/226, Lift .520/.520. 112 LSA.

ZZ-9X Hyd Roller:
duration @.050 225/240, Lift .525/.558 on a 112 LSA.

ZZ-X Hyd Roller:
Adv duration 290/290, duration @.050 239/239, Lift .558/.558, on a 112LSA.


The Super Profile is a lower lift cam then the ZZ9 and a tighter LSA (I should know I use to have that cam)

 

[87L98Z52]

Just got off the phone with tpis,they said to install either zz9 or zz409 cam,all you have to do is change the valve springs on the l98 heads.they said there is no machineing nec.no clearance issues.

 

[Mad-Mic]

Just got off the phone with tpis,they said to install either zz9 or zz409 cam,all you have to do is change the valve springs on the l98 heads.they said there is no machineing nec.no clearance issues.

thats scary then! i was told totally different from many people on the forums and from one of the guys at the shop about this.

is this with 1.5 RR's or 1.6 RR's? i may have to call them and ask cause if thats the case i'll throw the ZZ409 cam and LT1 intake i have on and have at it with a 150 shot of juice

 

[Mad-Mic]

Found a thread on this also

http://www.thirdgen.org/techbb2/showthread.php?s=&threadid=178262

seems very possible!again,my only concern is the alt,etc bolting up.does anybody know if they have the same mounting holes as l98 heads?

save yourself some trouble and buy a set of used DPort 113's and have alittle work done to them and for about 600 bucks total would be a decent flowing head.

if you go this route keep us updated! as i have heard nightmares about adapting LT1 heads to SBC1 blocks.

 

[-=Jeff=-]

thats scary then! i was told totally different from many people on the forums and from one of the guys at the shop about this.

is this with 1.5 RR's or 1.6 RR's? i may have to call them and ask cause if thats the case i'll throw the ZZ409 cam and LT1 intake i have on and have at it with a 150 shot of juice

Depends on the Springs.. If he uses the Springs from TPiS for the ZZ9 or ZZ409, no machining is needed. If they are another type, it is possible that machining would be required. What springs were you thinking of Mic

 

[87L98Z52]

I did not specify or ask about which rr would work without machining.ill have to call them back tomarrow.

jeff,why would the springs make a diff?i will ask them about this too tomarrow.

As far as the heads go.i was only looking into lt1 heads because i too want to use the lt1 intake instead of spending 1200 for the miniram.i figured by using the lt1 heads,i would get rid of the changing of the intake holes to bolt up to the l98 heads and because the lt1 heads are good flowing heads already.you can get a set of lt1 heads and intake off ebay for about 300.it does seem like alot of work and i prob wont do it but i just want to go through all the options before making a dec.I JUST DUNNO WHAT TO DO!