Alright, so I'm just a little confused about the heads on my truck, 89 f150 5.0.

I was going to do the spark plugs, so I got the plugs from the parts store but I opened one up just to make sure it was the same as what was in my truck, and I realized they were different. The ones I got had a .460" reach, whereas what was in my truck already had a 0.709" reach. I ended up finding the right plugs and swapping them in, now I'm just wondering what's going on in terms of what heads I have. They look like the stock e7 heads, but as far as I am aware the stock ones for this truck only used the .460" reach spark plugs, though I could be completely wrong here. Parts guy also thought it was some sort of swap too. I am 99% certain they are not gt40s.

From what ive been looking at online it seems like the mustangs got the longer reach plugs, and the only thing that seems to make sense is that the guy that used to own my truck got the heads from a mustang motor? He rebuilt and added some goodies to this motor but didn't give me much info about it all when I bought it lol. What would be the difference between the e7 heads on the trucks vs on the mustangs? I don't really get why they would swap the two.

If any one has any input that would be awesome... I just feel like I'm missing something here..

 

No difference at all.. same heads were used in both motors.

Can you see a capital letter cast into the top outer corner of either of the heads?

 

Hmm, well I'll have to take another look again.