Hey guys! Before i get started i wanted to let you know that ive done countless hours (yes hours) researching this swap. I have a HO intake and TB located and im pretty sure i want it. Ive read the guide on the installation to.

Now on to my question! How many people slotted the mounting holes, cut the gasket and just mounted the intake? I dont want to spend another $65 on a phenolic spacer. I mean, am i really going to notice a gain by port matching the intake? On a 450hp small block chevy (like i have hehe) i can see gaining some ponies but do you think i would on this daily driven 99Z with a 149hp 2.4? Im just wanting to get some cheap power basically. Thats why i have opted for the Secret Cams, the Ho intake and TB etc. Cams should be in the week I consider THAT cheap power (i didnt have to pay retail!).

Before Chris Fontana made spacers what did everyone do? I doubt people grinded, smoothed, welded, and polished everything up to match the head. Thats to much of a headach for such gain. So i guess my question is...Who just slapped on the mani (of course after modifying the bolt holes)??



And for the people who did the swap. Would you do it over again for the amount of gain you got? I know it more or less moves the power up to a higher RPM and you get a good lookin manifold but what did the butt dyno say?

Please let me know. Thanks in advance!

I just elongated the holes and polished it with some sand paper. It takes about an hour or so to get it to bolt on correctly. then I just ported the holes a little on the head and manifold so it would be a smooth transition.

The spacer is a good idea because it will help prevent heat soak in the manifold.. but if you are looking to go cheap, you do not need it.


HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED

So im assuming your head was OFF when porting and smoothing etc? I just want to be able to elongate the holes and install. I doubt the intake being HOT or WARM is going to affect the performance of it noticeably. Guess i could be wrong though.

So technically a person can just install it by fixing (elongating or whatever)the bolt holes correct ??

Also...did you like the gain? Was there any?

all i did was slot the holes, clean it, paint it, and installed now it does get hot, but i do plan on putting a spacer later. i run an auto and at the same time i did an underdrive pulley so i cant tell what it did, but i like it for the looks too, but mine is the LO mani.

jrbyers96 (The Fat One) wrote:So im assuming your head was OFF when porting and smoothing etc? I just want to be able to elongate the holes and install. I doubt the intake being HOT or WARM is going to affect the performance of it noticeably. Guess i could be wrong though.

So technically a person can just install it by fixing (elongating or whatever)the bolt holes correct ??

Also...did you like the gain? Was there any?

Being hot or warm actually does hurt performance. When you have high IATs it can induce preignition which kills your performance. Once your knock sensor "hears" knock it can retard spark up to 6 degrees (iirc) which makes a big difference. I highly suggest the spacer and port matching the spacer to the head then the intake mani. It will help. I dont see IATs over 110 on a 90 degree day at idle. and it cools down to about 90ish when moving.... in the winter it gets down to like 20 degree iats

So even when you buy the spacer you have to port match it to?? Dang, thats dissapointing. Im thinking about slapping it on for awhile and then possibly getting the spacer in the future. I just wasnt sure on what people did without the spacer.

Do you know what your IAT's are without the spacer?? Just curious....

the IAT chart pulls 0-6 degrees timing pending temp.


HP Tuners | Garrett T3/T04B | 2.5" Charge Pipes | 2.5" Downpipe | 650 Injectors | HO Manifold | Addco front/rear | Motor Mounts | HKS SSQV | Spec stage 3 | AEM UEGO Wideband | Team Green LSD | FMIC | 2.3 cams | 2.3 oil pump swap | 280WHP | Now ECOTECED

well u do not need it but you will be cuttin off some of the air flow id guess ud just be better off with the 2.4 manifold, the swap isnt worth it if its not matched with either porting/welding or the adaptor flange

Wrench Monkey wrote:
I highly suggest the spacer and port matching the spacer to the head then the intake mani. It will help.

So does the spacer eliminate the porting or not?

I truly do not believe (until there is dyno numbers showing) that this manifold is better than stock. Saying that using the manifold with out the adapter, or port matching the manifold and head is just dumb!!!!! There is no way it will flow better without one of the 2. There is plenty other mods you can do to get more power.



FU Tuning

I agree with the flowing theory. I see so many people with this and yet no one really says, "Yeah, feels totally different"! With spacer and without, i doubt there is a noticeable difference in power. Im lost on what to do. I want the looks and the added performance but if im not going to really notice anything then im literally throwing 150 bucks away.

Help guys...would you recommend and do this swap again? Is it worth it?

I've got an HO manifold, spacer and all of the stuff to do the swap, but I'm actually planning to do some before/after dynoing.

I'm hoping to do it in September, so I'll keep you guys posted.

I did the swap using a lo manifold and fontana flange in my 01 auto. I didnt do any dyno runs or anything but I did drop .2 off my 1/4 times with just the lo mani/flange in the same weather at the same track. It also sounds good and makes your exhaust tone a bit deeper, and looks good. I say if you dont plan to sc, do it; its a great mod for not alot of money.

SO, you just swapped out the mani and used the flange and did nothing else correct? You using the 56mm TB or your stocker??

i did the swap not to long ago. it was easier than i thought.



Im a Xbox 360 fanboy...and damn proud of it!!

Yea I just used the fontana flange and lo mani, no porting but you do have to slot out the bolt holes on the mani to match the flange. Theres also a little modification you have to do like cut the brake booster line and stuff. Research it and find the swap guide if you havnt already. Its realy not too hard though.

As for tb Im using a 2.4 thats bored out to 58mm, which was already on my car before I did the swap. And youll notice how much cooler the mani stays with the phenolic flange, after 6 runs at the track everyone was amazed lol. I had phenolic intake spacers on my 3400 grand am and they also helped keep the mani much cooler.

i have a link to a guide for this swap in my profile



Im a Xbox 360 fanboy...and damn proud of it!!

kflo wrote:I've got an HO manifold, spacer and all of the stuff to do the swap, but I'm actually planning to do some before/after dynoing.

I'm hoping to do it in September, so I'll keep you guys posted.

Please do and you will answer the question everyone wantsto know



15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"

Guys ive read the swap guide as noted in my first post. I just wanted some real answers from everyone. I dont wanna drop 70 on an intake and tb and 65 on a phenolic spacer and really not notice any gain. The whole reason behind the swap is to be cheap and easy. 150 bucks isnt cheap if the gain is seriously minimal. Now if id gain 2 tenths then id say its worth it!

I got a great deal,$150 for the HO mani.&t.b.,the phenolic spacer,AEM alum. alt. pulley and an Ebay alum. crank pulley.Just look and you will find a good deal somewhere



15.2@89mph 2.171 60ft. 9.830 1/8 R.I.P. "LULU"

I paid $10 for my 58mm tb haha.

But yea I dropped .2 with just the lo manifold and flange alone. Im sure it may not be the same results for every vehicle but mine helped.

Well, i guess ill go ahead and get the Intake and TB. I may try to make my own spacer at work. I have access to the same phenolic material that the FONTANA spacer uses. I guess i could get the right thickness and trace out the gasket onto it and cut out with some dremel tools or something. 65 bucks seems kinda steep to me. Thanks for all the info guys. Im open to any/all suggestions and comments.

BTW, i have a buddy in the machine shop bizz that would probably smooth up and open the intake ports a lil for nearly nothing. I could go this route and polish up the TB for cheap (cheaper than that spacer) and install directly on. Then i guess the only issue is "Heatsoak". If Heatsoak was a big problem then why dont they install phenolic spacers at the factory???

i love my HO mani but i am also with John Higgins, he is still running the 2.4 mani and he is what number 4 on top 10 for n/a 2.4? i will claim a top spot if not take ur spot when i actually make my way to the track for my first time ever!!! but i do believe that for boosted this mani is better as well as makes easier for charge pipe routing.

id also like to add that with more mods than just the exhaust and intake, the manifold will hold better results. id say with a raised red line along p&p head, stiffer valve springs(ho springs), and cams(secret cams at the least, HO cams mmmm ), i think the HO mani will be awesome, and be very potient.

for those with just intake/exhaust id say to keep a good flow id prob use the 2.3LO mani over the 2.3HO, or just the 2.4 one



.... but come on how sexy does that 2.3 mani look under there

Yeah Im doing the Secret Cam Swap next weekend. At the same time i installing my Pacesetter header and ebay aluminum crank pulley. I think im going to run 2 1/2 back to a dynomax bullet muffler (resonator)and then to a magnaflow, flowmaster or borla muffler. Here around my parts of Texas you dont have to have a cat...well, legally you do but no smog/emissions here.

So i guess my mods would be then:
Secret Cams
Air Intake
4-1 Header
2 1/2, no cat w/muffler
UD Crank Pulley
B&M Shift Plus
Both Mounts

Then if i get the Intake Manifold and TB i ought to be set for ahwile. Really not a whole lot of bolt ons left to do.

gmanz: Did you shave off the mounting spots where the MAP bolted on and just paint it? Looks really sleek and clean!

Also, if i want to keep my cruise control i have to buy a 95 2.3 CC bracket right? I cant ditch my CC!!!

yeah i shaved her clean thats the way to go