DennisC6

Ok i have a few questions.. first I have a 1988 5.0 mustang with GT40P heads, BBK 1515 headers, cold air intake 5 speed, and a catless exhaust will i beat a 4.6 with glass packs thats a auto?

Also with my mustang when its cold and i start it up and it runs fine but once it is warm it idles bad and dies often. any ideas what it could be..?

TrimDrip

first question, idk. I would think so but, every car is different and he may have somehting done you don't know about.

Second question, I would run the codes and see what it tells me.

jthorn9

Depends on what 4.6 you're talking about.

96-98 GT deffinitely.
99-04 GT will be close
05+ GT you're toast

Soldier GT

^^totally agree..

darkmach1

I figure it might be close with a slight edge to the 4.6 if it's a 99-04. Get a small cam and a nice intake to go with those heads. I purchased a code reader in amazon for $25, great little tool.

drhoward

You should be able to take him, but it will be close

z28th1s

1st question: Not enough info to make a good decision???

What year 4.6?
What gears and tires are on your car?
From a dig or a roll?

Your 2nd question: You have a '88 Mustang which came from the factory with speed density. Has your car been converted to mass air? If not, that is most likely your idle problem.