fuel pressure and flow were both checked.......the coil is good tried msd and stock........ torque is in the bottom end....yes??...than if flow is weak in top end......(3rd gear most load).....low HP......no????....put motor in at start of season and trying still to work the bugs out[:'(]

 

Yeah, heavier load in 3rd. But the flow through the heads will be the same. Thats why I would think it's something else. Did you check fuel pressurewhen it falls off? Does it just die? Miss?

 

I checked at idle and wot......and thats just it!!!! revs to 6200rpm in all gears.....but just seems to fall flat.....no miss....a/f meter stays rich...not too rich about same..

 

So I came home and rehooked up the pressure gauge(fuel) and at mid. to wot the gauge is at zero.....my thoughts are that my fuel line from the tank is too small.....this is why a installed the holley fuel pump to start.....same bug as before damn!!!! I think over winter I will sump the tank and install a return style fuel system with BIGGER fuel lines and a electric fuel pumpand regulator.....and alum. heads.... So thanks so much

 

what are your cam specs?

A motors horse power comes mostly from the heads, air flow in and out of the combustion chamber is key to making a car fast, as well as supplying it with plenty of fuel, a clear path in, and a clear path out. so if you have a stock 5.0 HO with some 10.5:1 pistons in it (wich is hard to tell what the end compression ratio will be if you dont know what heads are on it) an air gap intake, and a stock cam then you arent going to get massive power from it ever. also 110 liter per hour pumps are a great stock replacement. ever notice how if any thing is done at all to a stock stang, the lowest acceptable level of a fuel pump upgrade is a 255lph pump? you are starved for air, and starved for fuel. Also you should look into getting a bigger carb as well. I have a car here with a 10.5:1 motor in it, and i can tell you right now that if it had stock heads, and a 600 carb, it would be nothing much more than stock output.

 

Why did I miss the carb comment? anyone with admin status feel free to delete this and my previous post.

 

the cam has 220 duration @ .050 INT/EXHand .512 lift INT/EXH and I have installed 1.7 roller rockers so lift is at about .542.....lots of cam.....I drove the car to work today and bypassed the fuel filter and I only have 3psi fuel pressure at wot I think it a little low......so as per last post I think I will install an electric pump....