nemethjames1

why do u have to change headers with gt40p? and what headers are you limited to using? also whats the difference between gt40 and gt40p? ........... also are gt40p's about the same as stock heads port and polished?

vfast

I believe you can use a shorter plug and use the same headers..haven't tried it yet.....

4fit?

The angle that the spark plug enter the head on the P heads is why you have to run P-specific headers, although I have seen some folks run longtubes with P heads and have no problems.
The P heads have 1.84 intake vales and 1.46 exhaust valves.
The non-P heads have 1.84 intake but step up to 1.54 exhaust valves.
In my opinion, these heads have their best potential if you give then a p&p and enlarge the valves. But by the tme you sink all of that money into a set of these heads, you could have a good set of aluminum heads such as twisted wedge's to match your intake or some afr165s, which in my opinion are one of the best heads out there for a mildly modified 5.0

vfast

but me I like the 10's iron heads runs...people look and see a stock appearing engine.....no alum parts....I like the sleeper affect*L*