I know it may be a stupid question but.....


Apr 22, 2005
Hytop, AL
I just recently purchased a forged engine (crank, pistons, rods) with an f cam. It was run approx 500 mi after the rebuild with a cobra intake, 24lb injectors, 75mm C&L maf and a 70mm C&L tb. Everything is new on the engine. My question is how would it run going back to the stock intake and injectors and a speed density setup? I really dont want to break into the engine but with less than 500mi on the clock I will and sell the cam to get one that will run.
I dont want to switch to maf cause sd was the way the car was ment to run, and I want to keep- it as stock as possible.

  • Sponsors (?)

well what you should be looking at is swapping your 87 mustang over to a MAF set up. This is the time to do it. It is not as complicated as you may think and if you don't want to go and rob a 89-93 stang for the set up Ford makes a conversion kit. The MAF set up is much better then the speed density.
I dont want to switch to maf..... I want to keep- it as stock as possible.


Well, you've already purchased a motor whose short block (minus the cam you want to sell) is already non-factory.

You can look at it from another perspective. If you buy a Ford MAF setup from a donor car, it's still factory Ford 5.0 parts on a 5.0. If you buy the kit from Ford Racing, it's Ford parts. So, while it may not be original to your year, it is factory correct for the later 5.0 mustangs. There are so many benefits to MAF compared to Speed Density if you EVER in the future think you might want to modify the motor, that as 86bluecobra already pointed out, now is the time to do it.
That is just it, I dont want to go with the maf. It is my own personal preferance, I want to make it run great with the basic bolt ons and a custom tune from a local shop and keep it (computer wise... i.e. speed density) the way it came from the factory. I know it is a harder route to take but so be it. To many ppl are converting because of the ease of later upgrades.And I am not really wanting to sell to f cam I was asking if yall thought it would run in a sd setup. If it wont then I will sell it for one that will.


OK so you don't want MAF. Basically i doubt that cam will run very well on a speed density car. A speed density car is very dependant on vacuum and because of that you are very limited on which cam you can run. I know that comp cams has a few that work well with computer controller 5.0L (SD cars).
the F will not work well at all...you need to swap the cam or switch the SD. Paying for a dynotune on the car would not be cost effective and infact would cost far more than converting would...your best bet is a SD friendly cam or stocker. I did the conversion some time ago, the FMS kit installed like factory in less than a 1/2 hour with no wiring to do at all, simply plug and play....but it is more expensive.
the car wont run worth a damn with SD and that cam.

if your so stuck on running the stock SD computer. why are u even putting a cammed engine in, and putting bolt ons on it? they didnt come standard from the factory either.

if u want to stay SD get a stock cam and retard it 4*, will up the powerband a little. would probably suit it better than the f-cam if its stock heads and intake.
I agree with everyone else but if your set on SD then the cam HAS to go. The f cam will draw very little vacuum and cause major driveability problems especially in the lower RPMs. Secondly...why do you want to put the stock intake back on there? that intake is the BIGGEST bottleneck in 5.0's an explorer intake is cheap and easy to find and will make identical power to a cobra and would be a great bolt on upgrade for your car. I would look for an exp intake, get a stock cam and install it straight up or retarded 4*. Stick with stock injectors and SD computer and you should be alright. good luck