If your using an MSD Ignition they recommend that you don't use platinum plugs.

http://www.msdignition.com/forum/sho...light=platnium

 

thanx for all the help. i bought and installed the autolite 3294z 2day.

 

I have also heard sevaral times that its a bad idea to run platinum plugs with aluminum heads, but I don't know if that is fact or not.

 

checked this morning. nice that autolite have the designation on the plug. it's 3926 alright :-)

 

on that note. what spark plug boots are you using?
I have a set (came with the engine) of ford racing plug wires. They are angled (like the 135degrees). however the angled part is so close to the header flange that after a few hundred miles they slowly but surely work their way off the spark plug boot. I'd need some where the last part is just a bit longer. The 135deg seems perfect, just the last part a bit too short. when I push them in fully the angle part bends. that being rubber of course it will way its work out of that
What are you using?

Kalli

 

I tried those Ford Racing wires on my truck and hated them. They are about the worst fitting set I have seen for SBF. They are too bulky require the fat wire seperators and way too long. I'm running Accel super stock on the Mustang and they fit nicely, and aren't too long. They also can use the normal wire seperators.

What do you mean by boots? I have never changed them and always just used what the wire set came with. The only way you can change them is to cut the wires right?

 

ya i meant the rubber part that fits snuggly around the spark plug. they are too short on mine. I cut them all to length but I need to buy a different set as they are just popping of the spark plugs. when i fire the car in the morning it feels like 2 cylinders are missing. so engine off, pop them back on. that's bad already, but worse when they move away from spark plug. that must be a huge load on my box to spark across to plug and then again where it should spark

I'll try a different set so

 

I know this string is kinda old but I'm hoping someone will pick it up and help me out. I just rebuilt a 347 stroker, put it in my mustang and got everything hooked up. When I went to start it up, it would turn over but not fire up. I checked the spark, fuel and air. I've got all three. I've also checked the timing and that's good. The spark plugs I put into the Edelbrock Performer RPM heads are Autolite APP24. After reading this string it makes me feel that these might be to short of a reach and not allowing it to ignite the air/fuel mixture. Is this possible? Any help would be great. Thanks.

George

 

Here's what EDELBROCK recommends for their SBF heads:
http://www.edelbrock.com/automotive_...6000/60289.pdf

Here's what AFR recommends for their SBF heads:
http://www.airflowresearch.com/sbf_faq.php

 

thank you for the info. that did show me that i had the wrong plugs but even with the wrong plugs (they were to short) why wouldn't it fire?