stock head is fine i run one on my metra, i agree about the 19 phbg that will make it go fast im hitting mid 50's, i had some issues as well at first, not the same but close.
whne you put the head one did you check where the piston lined up? metra come with a bunch of metal gaskets but you need one more for it to line up right. i aggrre about checking timing, i have tried the entire spectrum and the metra is a little bitchy and will run shitty or not at all if its off just a bit along with points gap. almost all the way clock wise maybe a millimeter gap from all the way is a close place to start.