I'm trying to figure out the difference between FE and FT plugs. I've got an FT in my 64 F-250 and it gotten to be a real pain to start when it's cold out (20) and was looking for some opinions on spark plugs. I pulled one of the plugs and it's an autolite 45, so I'm wondering if I was sold FE plugs??

 

What engine do you have in it?

 

The concensus is that it's and FT by the block,intake,heads and exhaust manifold casting numbers that I posted on the 61-66 forum ( thanks numbers dummy ). The stroke measured by using a dowel in the #1 and #4 cylinder method is a shade under 4 inches, making my guess 391. I can't measure the crank snout since it's in the truck. I'm beginning to wonder if the parts guy that sold me the plugs didn't understand me when I said 361/391 FT and thought I meant 360/390 FE.

 

I can see where the plugs could effect performance and mileage but the truck sholud still start reasonably well as long as it has a plug designed for any standard FE engine.

 

bot, I am old enough to never say never, while I have no problem seeing a 390 in your truck I do with a 391. It's just not a desirable pickup engine.


Spark plugs didn't mean so much 40 years ago. The 45's while delivering max performance may not be correct, but should run the engine fine. JMO






John

 

I'm not positive, but best I recall the FT and FE pretty much used the same plugs. Of course, the FE typically used the resistor/supressor type, as they were a little more prone to having a radio in the dash.

 

Bottom line they should not cause a starting problem.

 

I had 45s in my 352 ive since gone back to the 42s it calls for. If memory sereves me and sometimes it does and sometimes not so much. I think I put those in because they were a hotter plug for the FE. I might be wrong have been before.

 

I guess I would add and properly gapped. How are the plug wires and the distributor cap? If the cap is cracked or cabon arced could cause misfire or hard starting. Is the choke working properly Have you looked to see when the choke **** is all the way out is the choke all the way closed? Just some things Id check if it were mine and doing that. Oh dont forget point gap and vacuum problems.