There is a guy on this forum , but not very often, IQ52 he's a professional engine builder LaRoy Engine from Challis Idaho & a very good professional head porter, he may be able to steer you in the proper direction... I know you need special head stud, rockers, longer push-rods, stock exhaust port location "I think" & also you can also get them in CNC Ported Versions STS B1-BS... Supposedly they/Brodix claims 90-120 HP over the competiters cast iron heads{maybe refering to MP Stage 5 ? & "I would assume non-ported versions" with smaller 2.14"/1.81" valves & 88cc chambers}, I don't know far a fact though... what are you building ?? what is the intended usage ??, I think they are also for 400-480+ Cubic Inchs, w/13:1 compression, roller valve train/camshafts, 4000-7500rpm range, 230cc intake volume, w/65cc comb. chamber, 2.20"int. & 1.81 ext. valves, B1-BS 295/233cfm flow@ 0.700"lift {non-ported versions}... w/80cc comb. chambers, 243cc intake volume, 348/279cfm flow @ 0.700" w/STS B1-BS {CNC fully ported version}... I used B1's many moons ago, I don't think they are even close to the old B1 head, I thought about the B1-BS at one time also, went a different route... This is all from my personal notes, so I'm sorry, if I am wrong on the #'s somewhere... Man it's so nice to have so many choices now... Good luck & Happy Moparing