So I built a new motorfor my car (90 5.0l roller block, 10:1 forged pistons, comp cam, air gap intake,600 cfm carb.) and all summer it's run slower then the stock motor(83 4v H.O.), the question I have is the heads on my stock motor are marked "3D15"..... the built motor is out of a 90 crown vic....are these heads "E7" or are they worst....the car digs hard but in third gear it seems to stop pulling(falls flat)....I know that there is lots of fuel....car runs good..... any ideas..... thanks guys

 

is your car tuned ???

and how about the shift points

 

those numbersare NOT a casting number but something else

casting number will start w/ a letter then a number...then a letter then an "e"
but you do not have the casting number, e7te's are actually good heads, contrary to belief, no good to spend money on, but for a boxstock head they are good

 

car is tuned.......and I have an A/F meter......shift points about 6200 rpm..... car 60's a 1.8 flat but third gear it stops pulling....tried bigger carb 670 cfm ran same ET same MPH. still falls flat in third car has 4:10s and should pull hard in all gears...

 

So will the crown vic motor have e7 heads or should I get off my a$$ and pull a valve cover....and I've rechecked my stock heads and they have D8OE????

 

I think if you used the injection off the crown vic it is not High Output (5.0 HO) this would explain alot.

 

so you made a stock motor have 10.5: compression, and thats it? what are you running for a cam, intake, rockers, exhaust? Did you have the heads ported, or gasket matched with the intake? What tranny are you running? With out knowing any of this, i already know you are choking the hell out of it with those heads. They are not E7 heads, you have D8 heads, if they were E7 heads they would read some thing like, E7TE or some thing like that. Get some heads, have them ported, and tell us the complete set up you have.

 

Pulling the valve cover isnt going to tell you anything, the casting number is under the intake ports.
http://www.aacncclub.com/FORD_HEAD_CASTING.html


What fuel pump are you running?

 

If you read I have a carb, an air gap intake......the heads are not my old d8 heads and the motor is an H.O. out of a crown vic......Gary H......the fuel pump is a holley 110 gph mech. pump.......and my mistake I will have to pull the intake to read the casting numbers...

 

I'd check fuel pressure and the fuelfilter. Going flat in 3rd wont have anything to do with the heads, if it pulls to the same RPM as it does in 1st and 2nd. Check the coil too.