Ive read a ton of posts and searched a long time. Im confused about the gap. Oreilies says .054 and i read here alot of you setting it at .054. the hays manual that covers almost all fox bodys say .044. what should I set it at. I have a 89 GT with a MSD coil motorcraft platinum plugs and march underdrives trans-go stage 2 shift kit.
the car does well but I cant get it to peal out. and 2nd gear wont scratch. I think I need to change my rear end to a 373.
my real question is. what gap should I use .045 or .055

 

.054 on sefi models and if it won't peel and you got an aod 4:10's would be a good idea the aod has a 2.40 first gear ratio so to get it to do what a 5 speed 3.35 first gear ratio does you must put lower gears and often a stall convertor too

 

The one that provides you with better results. There is no specific rule etched in stone that says it has to be set to a specific clearance..... you need to evaluate based on performance tests. OEM spec is .048" - .052" or .052" - .056" depending on the calibration number. I would ditch the platinum plugs though...... the TFI ignition was not designed to work with them and they do not provide any gains for the expense. Just a thought.

 

.050 for me...bump the timing up to 12-14 deg. with Super unleaded and those puppies WILL spin!

 

any precautions on setting timing up a bit? Ive never done this on any other car so I dont know anything about it.

 

spark knock if u dont use 93 octane

 

AOD car 12 deg. timing & 89 octane should be good to go...12+ = 93 octane

T-5 I would only use 93 octane at 11+

 

what does advancing the timeing give me?

 

advancing the timing deleviers spark earlier to start the cumbustion process earlier in an attempt to get all the burning done at proper time so it does not interfere with power producing stroke