alright i have posted this question elsewhere and am not getting a definite answer. gt40 turbo swirl heads call for agsf32c spark plugs, well the parts stores don't carry them anymore. so i was told to use 764's but these have a much different thread length. so are they interchangeable or what? if not what is a spark plug that will work for this
After a little bit of savvy internet hopping, I have determined that you want Autolite 104's. Googled "gt40 turbo swirl aluminum heads" and found, in fact, they did recommend "AGSF-32C or equivalent" plugs. Next, I went to Autolite.com. In the SEARCH area, I typed in AGSF-32C. This lead me to a cross-reference downloaded PDF. I then went to the Motorcraft section of said cross reference and found part number AGSF-32C. The correct Autolite plug listed across from that is 104. I then re-checked the Autolite site and entered the new plug number to verify that they were regular copper-core plugs: http://www.power-21.com/honeywellpower21i/PartDetail.aspx?b=A&pn=104 That should be your plug.
Ford changed their number scheme. The new part number is SP-447 Just go to autozone and ask for motorcraft copper plugs for a ;93 Cobra...same plug
He mentioned "turbo swirl" and I thought that implied the GT40 aluminum heads. The 93 Cobra's used the GT40 iron heads - not sure if they got the "turbo swirl" nomenclature as well. But, for the OP, when I researched the aluminum GT40s I got the same number for the plug that you listed. The cross reference for the Autolite's (and the steps I took to get there) are listed in my previous thread. So, if the irons and aluminums use the same plug, then you can get plugs for a '93 Cobra.
Well then you just need to find the NEW Ford part number for the 32C plug that was recommended. Ford went away from the ASGF-32C format over to something like SP-XXX
