Cracked Intake!!!???

[Hammer]

Hammer,
Do you know what the compession ratio in the 4.6 is when installing the 99-up PI heads??? Is it cheaper to do a intake and head swap on a 96-98 or install a 99-up 4.6 motor?? Is there any major changes in heads and intake swap that can be costly??? What is you opinion on short or long headers?

The compression ratio after the haeds\intake swap DOES indeed go up, which is OK in NA applications, but harder to deal with when going with forced induction.
(Which in some cases may require aftermarket internals if you wish it to last for any length of time.)
Unfortunately, I do not have the actual C/R numbers, but I'm sure a google search should bring up something...

As far as money is concerned, it's certainly cheaper to do a PI head\intake swap than a motor swap.

I don't have the exact data on what changes\parts are needed when doing a PI head intake swap, but from what I can remember, the extra parts involved are not expensive. It's just not "plug and play" like the FMS pieces.

If your car is a daily driver and lowered in any way, equal length or unequal length shorties are the way to go. A stock ride height car is much easier to deal with when combining long tubes and normal roads, dips, potholes... etc

In general, if you are looking to go forced induction, I would save up the cash and get the motorsport pieces. No muss, no fuss and forced induction friendly....

If you want to stay NA with bolt ons or try to "tune" it out with a 100 shot you can, but just watch yourself.... Find the CR numbers and find a professional to talk to about tuning a 99 PI swapped SN95 with forced induction.

Couple of good references are:
Hector or Mike Wilson at Dallas Mustang

JMS Chip Corp (Johnson Motorsports)