Its a great manifold, i love mine. I can really feel it pull alot harder around 2500+, i just wish it fit under the stock hood, ended up cutting mine so it could fit. Its pricey, but i think it was worth it.
you might even be able to find some useful info there!!!!
thats all these guys do is performance mustangs burns tunes special made chips....i know these guys personally i go to their shop about 3 times a month its not far from me 45 minutes or so!
but give them a call they have done alot of p-51's 717-502-8880 ask for george