If the profile specs are the same for both cams it has no effect on power.
The difference is in the fire order.
If you check the old 302 order you will find 1 pair of front cylinders on the same crankshaft pin firing sucessivly.
This has been found to be a problem in high performance motors, at times, so the pairing was shifted to the rear 2 cylinder where the block strength is much higher and the main bearing area is much greater..
Exhaust may make a perceptable difference in note/tone if you can note a before and after difference for the same exhaust system.
As a side note, the original thread question stated the use of a 302 for mass air application.
Here is an application that must use the 351 or 5.7 L cam because the Mass Air EEC (not a special EEC unit) uses the 5.7 fire order.
If this in not done, there will be an issue with the Ox sensors not sampleing the cylinders in the "expected" order for the EEC to control the fuel injection properly with the result that the motor does not run smoothly and increases fuel consumption.
Some may disagree but they are not understsanding the real issue without looking into a lengthy explanation as to why and what effects it has and why the need for a cam change in the old 302 motors.
Been there already and found out.

 

So the long tube headers on my stang mean that my o2 sensors wont read right and ill run rich? hmm hadnt noticed that in the 2 years they been on there, and we have very strict emmisions hear in az passes with flyin colors.

 

Bluegrass...I have a question for you..You seem to know alot about the 302 efi...I have allways been told when ever you change your injecter size your mass air meter should be calibrated to the injectors...I have been told this is BS that theres no such thing as a calibrated mass air meter...I have allways used PRO M meters that they say are calibrated ?? Pro M Racing - Mass Air Induction Systems Thanks Lew

 

Reply to post 17. Never said anything about long tube headers not reading correct as long as the 'cam fits the fire order' of the EEC.
There is a timing involved from when the ox sensors detect an individual cylinder's output to the time it sends back corrections to the EEC on a single cylinder basis. Yes it is that fast.
If the fire order is incorrect as in the case of a 302 carbed motor used with FI vs a regular fuel injection motor, the ox sensors will not detect two of the cylinders in the correct order because they are on the oppoisite bank. This causes an incorrect correction in the chain of events for each 8 firing cycles.
Ox sensors in headers at the collector point makes them lazy to correction due to running at a much cooler temperature (need 600° opererating temp), takes longer to go closed loop operation and the physical length from the head ports alters the feed back timing. Normally you will remember the 2 sensors are within about 18" of any port in a stock exhaust system for a reason.
How you percieve them to work is determined by your objectivity and knowledge of how the total system works.

Reply to #18.
Mass Air meter is supposed to measure the amount of air, and send that value to the EEC.
Independently, the injectors are to meter the correct amount of fuel vs RPM, ignition timing, Ox sensor feedback, coolant temp, intake air temp as well as BAP inputs.
If you increase the size of or the 'indicated' air flow with out some kind of reconcilition in the rest of the chain to keep the fuel ratio correct (one meters air, one meters fuel) then it's up to you to call it BS or not. It's still not correct unless the balance is restored by some means.
I give both of you the facts behind these things so you can see it's not just as simple as you may think it is. There is a lot going on that needs to be understood before making simple call as to the correctness of any single or mutiple changes.
A single change 'if' within the 'correction range' of +/- 10%, the complete system is able to shift to a correction, such that you don't percieve any great difference so the final position of "mine works fine" is taken, called BS etc without knowng what you really affected by the changes.
Remember there are software tables that are altered to make these corrections until they go out of range and set a code and light a CEL lamp indicating the system is out of normal range for whatever reason.
If no code is set and no lamp, you get away with a change, but the correction range is now at or near one limit and can't move much more in the same direction without setting a code and possably causing drivability issues.
A good refernce to get all this info from is the book on Ford Fuel Injection that lays all this out for you.
All this just dosn't come out of the air at random, by guessing or perception.
Good luck.

 

I was the one that told him it was BS and I'll stand by that, the computer holds the MAF transfer function so there's no way a company could "calibrate" a different meter to it unless some tuning device is used to alter the transfer function. The scaled meter/injector combos that aren't too much bigger than stock work because the computer has enough learning ability to keep the A/F ratios in check. But if you go too big it starts to get ugly and a chip or tuner is needed.

 

When I bought my Ford Mass Air conversion kit for my `90 5.0 truck I swapped to a 5.8 and called Ford to find out what I had to change ,They said all I had to do was change the firing order to the 5.8 because the signal to the injectors fires so fast that it wouldn`t make a difference. But I spliced the wirwing on the injector overlay harness against their suggestion to fire on the 5.8 firing order and it runs fine.

 

Yeah... that's bad advice and it's been proven wrong by people here on a few occasions.