[94pacecarSVT]

im looking to buy a set of 4v heads and need to know what the differences are in the 96-98 heads, 99-04 heads, and the navigator heads. the navi heads im looking at are off of a 2004 model.

[Boostang]

96-98 is b head.. 99 and up is c head

boost: b head > c head

n/a: c head > b head

[94pacecarSVT]

what kind of power could a 5.0 stroker with like a 9.6:1 comp ratio with nice cams and ported b heads make, with full bolt ons.

[Boostang]

that comp is a little low to be n/a.. but id guess high 3's low 4's?
just a guesstimate

[94pacecarSVT]

thats all im looking for n/a. i wanna put boost on it eventually but for now im just trying to make a strong n/a motor. i started this thread b/c im about to buy a set of b heads and wanted to know if i should wait and get c's. will the 99-01 intake work with b heads?

[Cricket]

if you want to boost it, make your build around boost, not around n/a now and boost later.

[98Cobra_sleeper]

very true, you need to build to your end goal

[94pacecarSVT]

i want a decent comp ratio. not super low because ill never run a ton of boost.

[carnage]

ok so let me get this strait the heads off the 96-98 are better for boost and the heads off the 99-04 are better for n/a

[98Cobra_sleeper]

yeah B heads make good high rpm hp, and C heads make better low end torque. Something cool i have 18cc pistons, i get 20mpg, and when i had the vortech supercharger on 15lbs of boost i made 460rwhp untuned. so you can have low compression and make good power on not a ton of boost.

[Boostang]

no the 99-01 intake will not work on a b head.. its hard finding the 96-98 intakes.. there are some on craigslist.. i got mine for 135 shipped.. i know i got lucky

[acidtonic]

I also love the B heads due to being somewhat of an underdog head. Here is my book of a post explaining why.

They are the only head which has not been fully utilized in my opinion. The whole intake design and IMRCs really screwed those heads but boost easily gets around those issues.

Some people are building custom intakes with 2 fully separate runners for each port on the head. B heads actually have 2 ports per cylinder with each port using a dedicated intake valve. No other 4v head out is as large or setup like this. The fact that being a horribly matched combo on a head with crazy amounts of volume and still producing 305hp (only 15hp less than the much better matched 99+ setups) I'd say they have lots of potential.

Ford dropped the ball by having both ports use the same intake runner which just destroys the specific capabilities of each port. People building custom intakes are splitting off the two ports and giving each a separate runner tuned for a specific purpose. Like primaries with a long "torquey" runner for off the line performance and low end grunt, then the switch over to a short runner tuned for high horsepower. In the opinions of some of these builders the stock intake tries to only produce horsepower.

IMRCs were used to band-aid the fact that they have no variable length runner intake like the FR500 for C heads. Instead of shutting off the secondary ports by a butterfly they should have just used a proper intake.

The other major issue is only one of these ports has a fuel injector. So the one lacking has no fuel to clean it and tends to gum up very quickly which kills power. Just adding an injector bung to spray the secondary port fixes the gunk problem and gains 20hp or more without doing anything else.

So basically these heads have the capability to blow away any other 4v head possibly even the beloved R heads when the whole combo is actually matched for the heads. Right now the entire combo around them is just wrong for how these heads need to make power. Yet with all that stuff wrong they are not too far behind C heads in current mismatched form.

Sorry for the book but that’s my opinion on why I like these heads. People as we speak are working on fixing these issues and being so cheap and easy to find they might be a good choice for even an na motor in the coming years. I also think they sound much better than all the other 4v heads but that’s just my opinion.

['97'Cobra]

Wow that was the best write up i have ever read concerning 4v heads
someone stayed up late doing homework...

[98Cobra_sleeper]

is there a better intake in the works for these heads?

['97'Cobra]

i forgot were i saw it online but they make a "stage 2" intake it was like $600 or something close. Im trying to remember the site i want to say brothersperformance.com im not entirly sure though but its out there. I havent heard any reviews on head or seen it throw down numbers so im sceptical to just throw that kinda money at it.

[acidtonic]

Actually nothing exists currently but a company called sullivan is working on one which essentially is like the Duke Nukem Forever of car parts.

In other words its "been coming out soon" for like 10 years now maybe longer.

Many just mod the stock intake and make it into a short runner which can get you an easy 15-20rwhp without losing anything down low.

Also I want to clarify since it sounds like I wowed you guys about the B heads. Its all potential but nobody really has made the stuff needed to harness them. In 90% of non boosted builds they are the worst choice of head.

Even with all the issues they are actually great for boost you just need to port them and the intake. Since they flow like gutters already you will actually hurt things by just hacking away material and instead you need to leave the intake ports alone as they are large enough. Dont even smooth the rough surface on the primaries since that will hurt fuel atomization (mixing) but you can smooth out the secondaries if you never plan to spray fuel through them.

Instead smooth and polish the exhaust ports while making them slightly larger and fix the shape issues like short turn radius, delete the IMRCS, gasket and port match everything, and forge the bottom end. That will get you a very nice boosted setup but it will suck without boost.

If you dont plan to boost ever just go with a C head. The other thing about boosting is I never said what kind of boost. C heads rule the world of Roots/TwinScrew blowers since nobody makes an intercooler for the B headed versions. Only the C heads have enough room under the intake for an intercooler which is pretty much a requirement if you're boosting a forged setup and want to make any power.

Thats why you see less people using the B heads because tons of the mustang guys are all about the roots/ts blowers. Now if you're going centri or turbo..... grab and port some B's

[DickH]

wait wait... im retarded now, but why are B heads better for boost? how much more than C heads do they really make pound for pound?

[Mach Boy]

There's also a difference between the Mark 8 B heads and the 96-98 Cobra Bs. The Cobra Bs are better.

[97mustanggt]

how do you shortrun tha 96-98 bheads to get that 15-20hp without loosing bottom end torque?

[Mach Boy]

^Any head for that matter?