98 cobra b heads or c heads?

[mark23svt]

I know this topic has been discussed to death but I just can't decide what I want. I don't mind a supercharger I just want as much n/a power I can get out of a 4v for now. You guys that have done do you regret anything or wish you would of just built the b heads. Is it a lot for expensive to swap to the c heads. I would want around 325-350 rwhp n/a then maybe a couple yrs down the road supercharge.

 

[Noreast]

I regret not doing c heads. More power for flow for n/a. Plus you can bolt an eaton on if you wanted to later on. Use the 96 cobra intake cam. If im not wrong they have more lope in them.

 

[Jonesy98]

I regret not doing c heads. More power for flow for n/a. Plus you can bolt an eaton on if you wanted to later on. Use the 96 cobra intake cam. If im not wrong they have more lope in them.

duration is more in the 96-98 cobra cams.

 

[4vRedone]

C heads are better but you could prob do cams in a b head and get 335whp

 

[mark23svt]

Well the eaton idea is great, I can do all boltons that and just start buying c head swap items.

 

[na svt]

C heads are better but you could prob do cams in a b head and get 335whp

more like 350-360rw

 

[mark23svt]

350rw is actually what I want and then maybe a vortech.

 

[mustangsvt281]

dont forget that if you do end up going vortech or procharger then i would forge the bottom end, just for added peace of mind.

 

[97desertCobra]

If n/a is the name of the game then C heads all day long. Forget the B heads. Cams and C heads can make 370rwhp pretty easily. When it comes to boost then the playing field levels out a lot however, the C heads still hold an advantage. Same with the C head intake that is found on the 01 Cobra. Which brings anohter point, far more intake options with the C heads compared to the B heads.

 

[mark23svt]

What do u mean by more intake options? Are the 01 heads fine or is it better to save for some 03 cobra or mach heads.

 

[Cobi-Wan]

What do u mean by more intake options? Are the 01 heads fine or is it better to save for some 03 cobra or mach heads.

Cams in the 01 cobra will be bigger than the cams in the 03.

 

[mark23svt]

Let me ask u guys that have done it, approximately how much of a difference would it be between c head swap or a supercharger on my b heads.

 

[Tabres]

I wish I would have just swapped to C heads rather than have my B heads ported.

 

[lou cypher]

I wish I would have just swapped to C heads rather than have my B heads ported.

Let me know if you want to do that......

I'll buy those ported b heads off you in a heartbeat.....

Just say the word....

Sorry OP....

 

[mark23svt]

No prob, its a hard decision since I already have longtubes, and cai. and since its only like 30-40 rwhp difference.

 

[97desertCobra]

What do u mean by more intake options? Are the 01 heads fine or is it better to save for some 03 cobra or mach heads.

If you have a choice between 03 or 01 I would go with 03. They are a little better then the 01.

As for intake options the B heads have 3 options, stock, MMR sheet metal, and custom sheet metal. The MMR intake and a custom sheet metal are both expensive. There isn't much information available on actual performance gains with the MMR intake and I suspect it gives up a good amount of torque for higher rpms and higher peak hp. So really a modified stock intake turning it into a short runner is the way to go IMO. The intake is really one of the biggest reasons the B head DOHC is a little bit of an under performer in n/a form.

Now for the C heads there are more options and better options although prices can be pretty steep especially if you are looking at the FR500 intake. Sullivan also makes a good intake but its not very good for n/a applications. So turning the stock intake into a short runner is the best choice for a street car IMO unless you have the money to buy the FR500.

 

[97desertCobra]

Let me ask u guys that have done it, approximately how much of a difference would it be between c head swap or a supercharger on my b heads.

Are you wanting to compare boost on a C head 4.6 vs boost on a B head 4.6?

 

[mark23svt]

No my question is more like, is the extra hassle and money worth doing the swap and only putting out like 30rwhp.

 

[Chris _Scott]

The swap isn't that bad at all, just take your time with it and make sure you have everything before hand.

Switching to 03 heads on my car was a big step for me, it really opens the door to more options down the road.

 

[97desertCobra]

No my question is more like, is the extra hassle and money worth doing the swap and only putting out like 30rwhp.

For the goals you stated in your OP sticking with B heads might right for you. Yes there are more options with the C heads and they do make a little more power then the B heads n/a and with boost. If you go full bolt on B heads with a short runner intake it is possible to make 310-320rwhp. Full bolt on C heads with a short runer intake it is possible to make 330rwhp. Obviously making the switch to C heads in this example is a lot of money just to see an extra 10-20rwhp. But you could use the 96-98 Cobra cams in the O3 C heads for another 15-20rwhp and make your goal of 340rwhp. The parts are not that expensive if you buy everything used but if you are planning on paying someone to do the swap it can be a lot of money in labor. Most people will want to drop the engine to swap the heads on 4.6 DOHC's because there isn't much room to work with in the engine bay.

Boost is the best bang for your buck hands down. With used centri kits going for cheap in the market section its a very good way to make good power without too much money and without huge modifications to the car. With good supporting mods and a good tune you could make 400rwhp with a measly 6# of boost from a centri blower. It takes a lot more money and effort to do that n/a with the 4.6, especially with B heads.

Currently my car has been down with a blown engine for over 3 years. Just a couple weeks ago started the process to tear it apart in order to part it out and sell the body as a roller. The blower just came off a couple days ago. If I could do it all over again I would have waited to do the blower last. First would be(sticking with B heads) full bolt ons with a short runner shooting for 310rwhp, Next would have been weight reduction and good suspension upgrades. Then on to a forged shortblock and then finally fuel system and blower.