Diff between Cobra and GT engine??

Engine Specs for 1993 Cobra (Long Post, do say I didn't tell you)

Copied from www.1993Cobra.com
http://www.1993cobra.com/data.htm

Engine Specifications

The 1993 Cobra came with a modified 5.0L engine with GT-40 heads and GT-40 cast aluminum intake manifold along with a new camshaft. Here are some specs for this engine:

Cylinder heads:

GT-40 heads previously sold by Ford Motorsports SVO with 1.84 intake and 1.54 exhaust valves. Heads were milled from 64cc down to 62.5 cc to raise the compression ratio a bit although the official compression ratio is 9.0:1 and were topped off with a set of Crane 1.7 ratio full roller rockers. Heads used a pedestal type of mounting system for the rockers. Part number for the cylinder heads is F3ZZ-6049-B up till 04/13/93 and F4ZZ-6049-B after date 04/13/93

Camshaft:

Ford designed a new camshaft grind to bring back some of the low end torque that was now lost using these higher flowing cylinder heads. Part number for the cam is F3ZE-6250-CA. Specs are as follows:

Intake/Exhaust duration in degrees of crankshaft rotation: 270/270 and at 0.050 lift 209/209
Intake/Exhaust lift at valve with 1.7 rocker ratio: 0.479/0.479"
Lobe separation is 118.3 degrees with 115 intake lobe center and a 121.5 exhaust lobe center.
Timing events at 0.050 lift are:
Intake: (BTDC):-10.5 / (ABDC): 39.5
Exhaust: (BBDC): 46.0 / (ATDC): -17.0

Intake:

Ford cast an aluminum version of the popular GT-40 intake with the staggered ports. Part number is F3ZZ-9424-C for the upper and F3ZZ-9424-D. There are 2 versions cast for the upper intake. The first version has a flat side on the plenum an apparently was causing harmonic noise at certain rpms and was revised with the more common stepped side plenum. The lower intake had a runner diameter of 1.64 inches and original lower intakes are distinguished from their Motorsport versions by having the firing order cast into the intake near the cutout for the distributor. Ford Motorsport also offered 2 different versions of the lower intake during it's production run. Sometime in the late 90's they went to a smaller cast runner where it meets the cylinder head. A side by side comparison would make the difference readily noticeable.

Fuel/Air intake:

The 93 Cobra got 24 lb/hr fuel injectors with a blue top. Early production Cobra's had unpainted injector bodies with the blue top and later versions and Motorsport versions had the injector body painted black. Fuel rails were standard as well as the fuel pump.

Air intake was identical to the production 5.0 except for the size of the mass air meter which was upgraded to 70mm vs. the 55 mm installed on the regular 5.0L. A vertical bar was added to the mass air meter to allow for more accurate metering of the incoming air. The throttle body installed on the Cobra was also upgraded to 65mm vs. the 60mm size installed on the regular 5.0L.

[b/]Exhaust:[/b]

The mufflers were retuned for less restriction and carried part number F3ZZ-5230-A (RH) and F3ZZ-5230-B (LH). Engineering numbers (numbers stamped on the mufflers) are: F3ZC-5230-CC (RH) and F3ZC-5232-DC (LH). They were 2.25" in diameter and had lengthened hangers to clear the rear bumper of the 93 Cobra. The headers and H-pipe were the same as regular 5.0L Mustangs.

Other:

The water pump and crankshaft pulleys were a different diameter than the regular 5.0L. The crankshaft pulley was reduced in size by 14% to underdrive the other accessories for more power but the drawback was a slower spinning water pump. To solve this problem, Ford also reduced the size of the water pump pulley by 14% to bring back the lost coolant flow. Part number for the crankshaft pulley is F3ZZ-6A312-A, water pump pulley is part number F3ZZ-8509-A and part number for the now shorter belt is F3ZZ-8620-A.