People have said that its overcarbed but I'll disagree with that statement being no one has been able to make a naturally aspirated 200 ci Ford inline 6 go as fast as mine has!
The carb is set up as follows,
White secondary spring (lightest Holley makes).
#69 primary jets.
6.5 power valve.
#34 center squirter.
On the street I run a 11" K&N X-Flow aircleaner assy and when I race it I remove the aircleaner and run a K&N stub stack. This is good for a 2 tenths increacse in the qtr mile.
The K&N X-Flow aircleaner assy was good for a 3/10 increasce in the qtr mile over a Edelbrock 10" air cleaner assy with a K&N air filter element.
This speaks volumes about how much better this head flows over the stock head!
I ran into several clearance issues when I installed the head and intake. The 1st was the lower part of the throttle arm contacted the intake. You can either grind a small groove in the intake or grind some material off the throttle arm on the carb.
The next issue was the secondary spring vacuum canister hit on the export shock tower brace. I ended up cutting a large notch in the brace.
Another issue on the early Mustangs is the clearance between the shock tower and the lower part of the intake. It is very close, but that can be remedied by shimming the right engine mount with 3 1/2" flat washers and tilting the engine way from the shock tower slightly.
EDIT: Today (12/27/08) I installed new engine mounts and decided to experiement. I used a die grinder to oval out the holes (bottom picture) where it mounts to the block on the left (drivers side) to drop the left side of the engine down vs raising the right side up and it worked! It allowed the engine to tilt to the left to gain the needed clearance and since you wasnt shimming up the right side it gave me a 1/4" additional hood clearance also.
Being I race mine I also made a engine torque strap that keeps the engine from moving.
The head needs a special ARP head stud kit that contains two differant lenghths of head studs due to the redesign of the head.
