Hi just wanting some info and or opinions on upgrading my intake manifold (4.6lt windsor 1997). I have a 75mm t/b on and have noticed how rough the internal surface is of the factory inlet manifold. Also i think it is only like 65mm opening. Can i get it ported and smoothed out or should i just go a new one? if so what will suit? keeping in mind that i'm about to put on a procharger kit. I am also curious about the heads aswell. .... everyone seems to say go the pi heads from a 99 or so....thoughts

 

if you're going to go through the trouble to do the manifold save yourself some time and upgrade heads and buy an aluminum intake manifold. i think the npi manifold would work, but you'd need an adapter. IF you put the blower on it might as well rebuild the whole motor...

 

I was under the impression that npi heads are better for boost?
And I thought the 4.6 had the aluminum intake mani.....

Ive never done any porting to the TB or intake mani. I think Jbrew has. Wouldnt hurt anything to at least smooth some things out.

 

4.6 does, but didnt they go to plastic when the did the pi heads?

 

The trucks have aluminum intakes. Mustangs got the plastic ones.

 

ah, ok.

 

When I rebuilt mine I did the pi swap and the intakes are different. Npi won't work unless adapters are used, and the adapters are almost the same price as the pi intake.
As far as porting the elbow between the intake and the throttle body I ported and pollished mine to the same size as the 75mm throttlebody then ported the intake to match it.

Also when you switch the heads to a pi head onto your non-pi intake it will boost your compression to a non boost friendly 10.5 to 1.
If it where me I would just port the elbow and intake, bolt the procharger up then start building a new pi headed motor for when you want more from the procharger.

 

yeah the inlet is aluminium, thanks for all the input, i will look into porting the factory one and as lightning_clone says, start building up another motor over time (with all the good bits on it )