Don't think so. I'm pretty sure you need the FRPP headers specifically for the GT40s (can't remember if there are headers for the GT40s and GT40Ps specifically).
I have the BBK shorties on my P heads. I had to flip the spark plug wires so that the 90 degree boot end is on the plug and not the distributor on the 6,7 and 8 cylinders. This is pretty ghetto, but it works. If you can manage it, get the P headers.
ford racing parts has "p" specific headers, they are the p51 or p50s cant remember they allow u to use stock plug wires although but 2 of mine got burnt through from sitting on the header they were ford wires
I believe the BBK equal length shorties will work from what I remember. I have a pair of MAC unequal length shorties on my GT40p heads. I have to run 90* boots and had to slightly ding the pipe to clear #3 & #7...maybe only one of those, I can't remember. I took this cheaper route to get the car up and running economically and may get the FRPP headers later if I can find a deal on a pair.
I have BBK unequal length shorties on my GT40-P heads.I bought a set of Taylor plug wires with 90 degree boots and everything fir fine,no issues at all.
I have Mac Lt's P spcific because i was melting plugs they were not cheap you could always get header Rap that worked when i had the stock Headers. But i wanted Lt's anyways.
ford racing and mac both make p specific headers. i have mac equal lengths which i definately dont like. i had to beat some pretty decent dents in them to make them morw as well as use a 90 degree plug boot on the 3 and 7 plugs and accel wire sleeves to keep from burning them up monthly. if you look aT the ford racing p specific header they just changed they way the last 2 primaries go into the collector in order to be able to run a standard plug wire without them touching the header. kinda sux you have to pay an extra hundred dollars for a simple fix like that but i have every intention on switching to a p specific header as soon as my wallet allows. also if u can get a hold of 93-95 cobra heads. GT40 not gt40p's the spark plug angle isnt changed and therefore requires no special headers. look for the missing P designation and 3 bars instead of 4
I run blue oval from ebay. They were less than $150 and fit much better than the ford headers. The welds are real nice as apposed to the ford headers. My 11 year old daughter tig weld nicer than whoever welds the ford pieces.