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AAM Cobra 98
03-18-2006, 08:29 PM
Hi guys,

I am in the middle of building my engine, i have all the mods in my sig plus IMRC deletes, i have read alot about the heads on our 96-98 vs. 99-01 heads, from what i understand that they flow better. i have few questions:
1- is it worth changing my heads and if so what about the intake & cams?
2- are they a direct bolt on or i need to do some modification?
3- from what i understand our heads are 52cc and 99-01 heads are 54cc and by swaping them i will be lowering my Compression Ratio will the gain from the heads compensate the lose in Compression ratio ...

this Cobra is for street racing and it will be getting a bottle soon (as soon as i finish the break-in) i will be using a wet 200 shot and i will upgrade my fuel pump to walbro 255lph any suggestion?

thanks guys ...

tcrews
03-21-2006, 09:24 AM
almost a direct bolt on, I'm trying to remember what you'll need. I think you'll need to keep your valvecovers as the newer ones interfer with your fuel rails. You'll also need a '99 up intake as yours will not work with the newer heads.

The better choice would be '03/04 Cobra heads as they are some of the best out of the box heads you can get. Your compression ration isn't going to change so don't worry about that.

You will need some extensive tuning to adjust for no IMRC's and the different flow characteristics of the new heads and intake.

AAM Cobra 98
03-21-2006, 01:58 PM
thanks for the info .. but my main question is (is it worth it) what are the gains i am looking at in whp and TQ .... and where can i find a set of 03 cobra heads if the swap is worth it ..

tcrews
03-21-2006, 02:08 PM
Honestly I don't know if it's worth it or not financially. Yes you'll have a little more hp and tq but at what cost?

The biggest problem witht the B-heads is they flow too well, not enough velocity to generate torque down low but they will flow very nice with nitrous on it for making horsepower...

Honestly I prefer the look of the '96-'98 intake so I'd just keep your heads and intake and do a regular build up (forged block, .020 overbore, nitrous cams, etc..).

AAM Cobra 98
03-21-2006, 09:45 PM
thanks tcrews, thats is what i am doing at the moment complete forged .02 with ARP and billet oil pump plus LDC head cooling kit ...

you have mentioned cams ... which cams do you recommend as i will be N/A most of the time with the occacianal Nitrous (i didn't do any porting or polishing for the heads nor the intake, do you recommend doing them as this will be done manually as i live in Bahrain)...

tcrews
03-21-2006, 11:04 PM
Then I wouldn't worry about cams. Just a good solid build to keep your NA power levels nice and then hit the nitrous for that extra OOMMPHH! :)

smashedheadcat
03-22-2006, 06:45 AM
I would not change heads. Stick with the b-heads. Believe it or not, these are some of the best flowing OEM heads out there in the upper rpms. I think the '03 cobra heads would help build low/mid range rpm torque but gains would be minimal up high. If you go with cams, I would recommend the Houston Performance Nitrous cams. Even if you plan on staying N/A. Joe Lynch makes some pretty good N/A power numbers with these cams. His car does really well on the bottle as well. My recommendation would be this. Go +.020 over on the black, keep the B-heads (maybe have them cleaned up a touch) and if you've got the $$, get the nitrous cams. As for bang for the buck...... you'd be much better off with a blower. Anyway, these cams will be worth 20-30rwhp at peak, but when you look at the price tag.... it's not too good of a bargain.

AAM Cobra 98
03-22-2006, 09:57 AM
thanks guys ... i was nearly going to swap my heads thanks fot the info ... it seems i will be going with the cams from steve (houston performance) as i already got all my build up stuff from him ...

My question is do i need to change anything else with the cams (springs ...etc)..

AAM Cobra 98
03-22-2006, 03:45 PM
do you recommend the bilet cams or the regrind .. and what is the diffrence between them ?

AAM Cobra 98
03-23-2006, 06:51 PM
hi guys ... i have read alot about swaping to C-heads for N/A and that is the best way to go if staying N/A .. but was wondering of what kind of gains we are talking about is 30+whp for swaping to 99+ heads, cams and intake .. or just 10whp ...

smashedheadcat
03-25-2006, 07:20 AM
I think with the c-heads you'll pick up a little power (10rwhp or so) down low, but I think the B heads will perform better (by 4-5hp) up top. With a little bit of porting.... the b-heads are awesome. Problem is, there really isn't really any intakes availalbe for the b-heads. You can use the FR500 intake on the c-heads, sullivan intake etc etc. Nothing for the b's.

ian white
03-25-2006, 09:49 AM
ford racing makes the m9424-t46 intake manifold for 96-98 cobras. its new and very expensive,phoned ford said its good for 20-25 hp

AAM Cobra 98
03-27-2006, 08:38 AM
that is too expensive for the gains, but the kit includes all the stuff you need This kit will include 34 lb. injectors, air meter and fuel rails plus the intake and it is made from magnesium ... i hate it that we B-headed cobras don't have any intake options ...